diff --git a/app/src/main/kotlin/docthor/app/App.kt b/app/src/main/kotlin/docthor/app/App.kt
index d3b140a..8426865 100644
--- a/app/src/main/kotlin/docthor/app/App.kt
+++ b/app/src/main/kotlin/docthor/app/App.kt
@@ -1,7 +1,5 @@
 package docthor.app
 
-import java.nio.file.Paths
-
 
 import com.github.ajalt.clikt.core.CliktCommand
 import com.github.ajalt.clikt.parameters.options.option
@@ -11,8 +9,9 @@ import com.github.ajalt.clikt.parameters.types.file
 import de.itkl.tfidf.Language
 import de.itkl.tfidf.TfIdf
 import kotlinx.coroutines.runBlocking
+import java.io.File
 
-class MainCommand : CliktCommand() {
+class ComputeTf : CliktCommand() {
     private val corpus  by option(help = "corpus")
         .file()
         .required()
@@ -21,10 +20,14 @@ class MainCommand : CliktCommand() {
         .required()
 
     override fun run() = runBlocking {
-        TfIdf().buildTfIdfDict(
-            corpus, language
+        val tfIdf = TfIdf()
+        val histogram = tfIdf.computeTf(
+            corpus,
+            language
         )
+        tfIdf.normalizeTf(histogram, corpus.toPath().parent.resolve("${corpus.nameWithoutExtension}-tf.csv").toFile())
+
     }
 }
 
-fun main(args: Array<String>) = MainCommand().main(args)
+fun main(args: Array<String>) = ComputeTf().main(args)
diff --git a/app/src/test/kotlin/docthor/app/MessageUtilsTest.kt b/app/src/test/kotlin/docthor/app/MessageUtilsTest.kt
deleted file mode 100644
index f3c02fe..0000000
--- a/app/src/test/kotlin/docthor/app/MessageUtilsTest.kt
+++ /dev/null
@@ -1,14 +0,0 @@
-/*
- * This Kotlin source file was generated by the Gradle "init" task.
- */
-package docthor.app
-
-import org.junit.jupiter.api.Test
-
-import org.junit.jupiter.api.Assertions.assertEquals
-
-class MessageUtilsTest {
-    @Test fun testGetMessage() {
-        assertEquals("Hello      World!", MessageUtils.getMessage())
-    }
-}
diff --git a/build-logic/src/main/kotlin/docthor.kotlin-common-conventions.gradle.kts b/build-logic/src/main/kotlin/docthor.kotlin-common-conventions.gradle.kts
index 9230cc5..1fc4e87 100644
--- a/build-logic/src/main/kotlin/docthor.kotlin-common-conventions.gradle.kts
+++ b/build-logic/src/main/kotlin/docthor.kotlin-common-conventions.gradle.kts
@@ -5,16 +5,11 @@ plugins {
 }
 
 repositories {
-    // Use Maven Central for resolving dependencies.
     mavenCentral()
 }
 
 dependencies {
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.7.3")
-    constraints {
-        // Define dependency versions as constraints
-        implementation("org.apache.commons:commons-text:1.10.0")
-    }
 }
 
 testing {
diff --git a/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/Histogram.kt b/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/Histogram.kt
index d4acf9e..d3721c4 100644
--- a/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/Histogram.kt
+++ b/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/Histogram.kt
@@ -2,8 +2,7 @@ package de.itkl.textprocessing
 
 import kotlinx.coroutines.flow.Flow
 
-class Histogram : Iterable<Pair<String, UInt>>{
-    private val histo: MutableMap<String,UInt> = mutableMapOf()
+class Histogram(private val histo: MutableMap<String,UInt> = mutableMapOf()) : Iterable<Pair<String, UInt>>{
 
     companion object {
         suspend fun from(flow: Flow<String>): Histogram {
@@ -11,6 +10,12 @@ class Histogram : Iterable<Pair<String, UInt>>{
                 flow.collect(this::add)
             }
         }
+
+        fun from(sequence: Sequence<Map<String, String>>): Histogram {
+            val histo = sequence.associate { map -> map["word"]!! to map["count"]!!.toUInt() }
+                .toMutableMap()
+            return Histogram(histo)
+        }
     }
 
     fun add(word: String) {
@@ -20,7 +25,6 @@ class Histogram : Iterable<Pair<String, UInt>>{
     }
 
     val size get() =  histo.size
-
     override fun iterator(): Iterator<Pair<String, UInt>> {
         return iterator {
             histo.forEach { (t, u) -> yield(t to u) }
diff --git a/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/HistogramCsvStorage.kt b/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/HistogramCsvStorage.kt
index b08b32c..fca404f 100644
--- a/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/HistogramCsvStorage.kt
+++ b/libraries/textprocessing/src/main/kotlin/de/itkl/textprocessing/HistogramCsvStorage.kt
@@ -1,11 +1,11 @@
 package de.itkl.textprocessing
 
+import com.github.doyaaaaaken.kotlincsv.dsl.csvReader
 import com.github.doyaaaaaken.kotlincsv.dsl.csvWriter
 import java.io.File
 import java.nio.file.Path
 
 class HistogramCsvStorage {
-
     suspend fun save(histogram: Histogram, file: File, progressOp: (Long) -> Unit = {}) {
         csvWriter {}
             .openAsync(file, append = false) {
@@ -16,7 +16,11 @@ class HistogramCsvStorage {
             }
         }
     }
-    fun read(path: Path): Histogram {
-        TODO()
+    suspend fun read(file: File): Histogram {
+        return csvReader {  }
+            .openAsync(file) {
+                val sequence = readAllWithHeaderAsSequence()
+                Histogram.from(sequence)
+            }
     }
 }
\ No newline at end of file
diff --git a/libraries/tfidf/build.gradle.kts b/libraries/tfidf/build.gradle.kts
index 438770d..738ede3 100644
--- a/libraries/tfidf/build.gradle.kts
+++ b/libraries/tfidf/build.gradle.kts
@@ -3,6 +3,7 @@ plugins {
 }
 
 dependencies {
-    implementation(project(":libraries:textprocessing"))
+    api(project(":libraries:textprocessing"))
     implementation("com.github.ajalt.mordant:mordant:2.2.0")
+    implementation("com.github.doyaaaaaken:kotlin-csv-jvm:1.9.2")
 }
diff --git a/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/Tf.kt b/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/Tf.kt
new file mode 100644
index 0000000..ab80429
--- /dev/null
+++ b/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/Tf.kt
@@ -0,0 +1,31 @@
+package de.itkl.tfidf
+
+import com.github.doyaaaaaken.kotlincsv.dsl.csvWriter
+import de.itkl.textprocessing.Histogram
+import io.github.oshai.kotlinlogging.KotlinLogging
+import java.io.File
+import kotlin.math.max
+
+private val Log = KotlinLogging.logger { }
+class Tf {
+    private val data: MutableMap<String, Double> = mutableMapOf()
+    fun update(histogram: Histogram): Tf {
+        val max = histogram.maxOf { (_, count) -> count }
+            .toDouble()
+        histogram.forEach { (word, count) ->
+            val tf = count.toDouble() / max
+            data[word] = tf
+        }
+        return this
+    }
+
+    suspend fun saveToCsv(file: File) {
+        csvWriter {}
+            .openAsync(file, append = false) {
+                writeRow("term", "frequency")
+                data.forEach { (t, u) ->
+                    writeRow(t, u)
+                }
+            }
+    }
+}
\ No newline at end of file
diff --git a/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/TfIdf.kt b/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/TfIdf.kt
index 3c24626..3212c60 100644
--- a/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/TfIdf.kt
+++ b/libraries/tfidf/src/main/kotlin/de/itkl/tfidf/TfIdf.kt
@@ -1,27 +1,30 @@
 package de.itkl.tfidf
 
-import com.github.ajalt.mordant.animation.progressAnimation
 import com.github.ajalt.mordant.terminal.Terminal
 import de.itkl.textprocessing.Histogram
 import de.itkl.textprocessing.HistogramCsvStorage
 import de.itkl.textprocessing.TextFile
 import io.github.oshai.kotlinlogging.KotlinLogging
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.take
-import kotlinx.coroutines.withTimeoutOrNull
 import org.tartarus.snowball.SnowballStemmer
 import org.tartarus.snowball.ext.GermanStemmer
-import java.awt.SystemColor.text
 import java.io.File
+import kotlin.io.path.exists
 
 
 private val Log = KotlinLogging.logger { }
 class TfIdf {
-    suspend fun buildTfIdfDict(
+    suspend fun computeTf(
         corpus: File,
         language: Language
-    ) {
+    ): Histogram {
         Log.info { "Processing $corpus" }
+        val destination = corpus.toPath().parent.resolve("${corpus.nameWithoutExtension}-terms.csv")
+
+        if(destination.exists()) {
+            return HistogramCsvStorage().read(destination.toFile())
+        }
+
         val filesize = corpus.length()
 
         val t = Terminal()
@@ -31,12 +34,18 @@ class TfIdf {
             Histogram.from(words)
         }
 
-        val destination = corpus.toPath().parent.resolve("${corpus.nameWithoutExtension}-terms.cv")
         t.progressBar("Saving ${histogram.size} entries", histogram.size.toLong()) {
             HistogramCsvStorage()
                 .save(histogram,destination.toFile()) { entriesWritten -> update(entriesWritten)}
         }
+        return histogram
+    }
 
+    suspend fun normalizeTf(histogram: Histogram, destination: File) {
+        Log.info { "Write tf to $destination" }
+        Tf()
+            .update(histogram)
+            .saveToCsv(destination)
     }
 
     private fun stemmer(language: Language): SnowballStemmer {