diff --git a/src/main/java/fr/u_paris/gla/project/io/NetworkFormat.java b/src/main/java/fr/u_paris/gla/project/io/NetworkFormat.java
index 0113744..11663dd 100644
--- a/src/main/java/fr/u_paris/gla/project/io/NetworkFormat.java
+++ b/src/main/java/fr/u_paris/gla/project/io/NetworkFormat.java
@@ -45,11 +45,19 @@ public final class NetworkFormat {
         // Tool class
     }
 
+    /** Convert a {@link java.lang.String} into a {@link java.time.Duration}
+     * @param duration the {@link java.lang.String}
+     * @return the {@link java.time.Duration} object
+     */
     public static Duration parseDuration(String duration) {
         LocalTime time = LocalTime.parse("00:" + duration, DURATION_FORMATTER);
         return Duration.between(time, ZERO);
     }
 
+    /** Format a {@link java.time.Duration} into a {@link java.lang.String}
+     * @param duration an object of type {@link java.time.Duration}
+     * @return a String that depicts the duration in format MM:SS
+     */
     public static String formatDuration(Duration duration) {
         return DURATION_INDIVIDUAL_FORMATTER.format(duration.toMinutes()) + ":"
                 + DURATION_INDIVIDUAL_FORMATTER.format(duration.toSecondsPart());
diff --git a/src/main/java/fr/u_paris/gla/project/io/ScheduleFormat.java b/src/main/java/fr/u_paris/gla/project/io/ScheduleFormat.java
index 8a86594..c97b233 100644
--- a/src/main/java/fr/u_paris/gla/project/io/ScheduleFormat.java
+++ b/src/main/java/fr/u_paris/gla/project/io/ScheduleFormat.java
@@ -41,6 +41,9 @@ public final class ScheduleFormat {
         }
 
 
+    /** Create a {@link java.time.format.DateTimeFormatter} object used to format Dates
+     * @return the formatter
+     */
     public static DateTimeFormatter getTimeFormatter() {
         return DateTimeFormatter.ofPattern("HH:mm").withResolverStyle(ResolverStyle.LENIENT);
     }
diff --git a/src/main/java/fr/u_paris/gla/project/utils/CSVTools.java b/src/main/java/fr/u_paris/gla/project/utils/CSVTools.java
index b3194f9..5332a41 100644
--- a/src/main/java/fr/u_paris/gla/project/utils/CSVTools.java
+++ b/src/main/java/fr/u_paris/gla/project/utils/CSVTools.java
@@ -32,6 +32,11 @@ public final class CSVTools {
         // Tool class
     }
 
+    /** get a CSV file from a URL, download and parse it, and keep values in memory
+     * @param url the address of the CSV file
+     * @param contentLineConsumer the variable used to store the data
+     * @throws IOException if it's impossible to download the file
+     */
     public static void readCSVFromURL(String url, Consumer<String[]> contentLineConsumer)
             throws IOException {
         ICSVParser parser = new CSVParserBuilder().withSeparator(';').build();
@@ -52,6 +57,11 @@ public final class CSVTools {
         }
     }
 
+    /** Save our current CSV variable's data into an actual file
+     * @param filename the saved file's name and path
+     * @param contentLineConsumer our data variable
+     * @throws IOException if we can't write the data into the file
+     */
     public static void writeCSVToFile(String filename,
             Stream<String[]> contentLineConsumer) throws IOException {
         try (FileWriter writer = new FileWriter(filename, StandardCharsets.UTF_8)) {