diff --git a/xerus/data.py b/xerus/data.py
index e2a9392..bbc70bc 100644
--- a/xerus/data.py
+++ b/xerus/data.py
@@ -5,6 +5,8 @@ import re
 import pyexcel
 from collections import namedtuple
 
+from . import merge
+
 def extract_from_file(path):
     """ Extract and yields notes from the file at path """
     pass
@@ -21,25 +23,39 @@ def extract_test():
                     date = f"{day} mars 2020"
                     yield NoteInfo(person, category, date, time, author, text)
 
+def sanitize_text(text):
+    return text.strip().capitalize()
+
+
 
 def authion_extractor(sheet):
     """ Extract data from Authion format """
-    pass
+    def sanitize_row(row):
+        return row
 
-def sanitize_category(name):
-    return name.strip().capitalize()
+    def process_rows(iterable):
+        return merge.fill_with_sentinel(1, 0,
+            merge.fill_with_master(1, 2, 
+                merge.fill_empty_cells(1, iterable)))
+
+    for row in process_rows(sheet.rows()):
+        try:
+            (day, time, author, category, text) = row
+            if text:
+                yield (day, sanitize_text(category), sanitize_text(time), author, text)
+        except ValueError:
+            print(f"Invalid row (Authion): {row}")
 
 def couasnon_extractor(sheet):
     """ Extract data from Couasnon format """
-    from . import merge
 
     def sanitize_row(row):
         (day, cat, matin, soir, nuit, *rest) = row
         if not day or not cat:
             raise ValueError
-        return (day, sanitize_category(cat), str(matin).strip(), str(soir).strip(), str(nuit).strip())
+        return (day, sanitize_text(cat), str(matin).strip(), str(soir).strip(), str(nuit).strip())
 
-    for row in tuple(merge.fill_value(0, sheet.rows())):
+    for row in tuple(merge.fill_empty_cells(0, sheet.rows())):
         try:
             (day, category, matin, soir, nuit) = sanitize_row(row)
             if matin:
@@ -102,7 +118,7 @@ class Notes(dict):
     CONFIG = (
         { "source": "/home/artus/Projets/python/xerus/test/",
           "extractor": authion_extractor,
-          "file_pattern": "(\d) (\w) (\d).ods",
+          "file_pattern": "\d{2} (\w+) (\d{4}).ods",
         },
         { "source": "/home/artus/Projets/python/xerus/test/",
           "extractor": couasnon_extractor,
diff --git a/xerus/merge.py b/xerus/merge.py
index bf20589..4a6bd6c 100644
--- a/xerus/merge.py
+++ b/xerus/merge.py
@@ -15,10 +15,68 @@ def rows_merged(rows, conf={}):
     pass
 
 
-def fill_value(idx, iterable):
+def fill_empty_cells(idx, iterable):
     """ Fill the value at index with the last found """
     value = None
     for row in iterable:
         value = row[idx] or value
         row[idx] = value
         yield row
+
+
+def fill_with_sentinel(sentinel, target, iterable):
+    """ Find a cycle in sentinel column, and fill the target column with unique value """
+    buff = []
+
+    value = None
+    seen = set() 
+    last_seen = None
+    for row in iterable:
+        if row[sentinel] != last_seen:
+            last_seen = row[sentinel]
+            if last_seen in seen:
+                # Flush the buffer
+                for r in buff:
+                    r[target] = value
+                    yield r
+                buff.clear()
+                seen.clear()
+            seen.add(last_seen)
+
+        value = row[target] or value
+        buff.append(row)
+
+    for r in buff:
+        r[target] = value
+        yield r
+
+
+def fill_with_master(master, target, iterable):
+    """ Fill the target column cells with unique value while master column is unchanged """
+    buff = []
+    target_value = None
+    last_in_master = None
+    for row in iterable:
+        # Search for target value
+        if last_in_master and row[master] != last_in_master:
+            if not target_value:
+                print("Warning: No target value ->", 
+                      list(map(lambda i: (i[master], i[target]), buff)))
+            # Fill target and yield buffer
+            for buff_row in buff:
+                buff_row[target] = target_value
+                yield buff_row
+            buff.clear()
+            target_value = None
+
+        target_value = row[target] or target_value
+        last_in_master = row[master]
+        buff.append(row)
+
+    for buff_row in buff:
+        buff_row[target] = target_value
+        yield buff_row
+    
+        
+
+