diff --git a/doc/source/containers.rst b/doc/source/containers.rst
index c8ff53f..276da2c 100644
--- a/doc/source/containers.rst
+++ b/doc/source/containers.rst
@@ -2,28 +2,28 @@
 Container types
 ===============
 
-Containers allow to manage collection of values of homogeneous type.
+Containers allow to manage collections of values of homogeneous type.
 Three container types exist.
 
 A container is a non-mutable structure once it has been locked.
-Consequently just insert procedure are needed
+Consequently, only insertion procedures are needed.
 
 Lists
 -----
 
-Correspond to an ordered collection of values belonging an elementary type.
+Correspond to an ordered collection of values belonging to an elementary type.
 
-At its creation
+At its creation, ...
 
 
 Sets
 ----
 
-Correspond to an unordered collection of values belonging an elementary type.
+Correspond to an unordered collection of values belonging to an elementary type.
 
 
 Dictionaries
 ------------
 
-Dictionaries allow to associate a `key` to a `value`. Values can be retrieved through its associated key.
-Values must belong an elementary type and keys must be *OBIStr_t*.
+Dictionaries allow to associate a `key` to a `value`. Values can be retrieved through their associated key.
+Values must belong to an elementary type and keys must be *OBIStr_t*.
diff --git a/doc/source/elementary.rst b/doc/source/elementary.rst
index c254008..56f10ad 100644
--- a/doc/source/elementary.rst
+++ b/doc/source/elementary.rst
@@ -12,7 +12,7 @@ Atomic types
 =========   =========   ============   ==============================
  integer     int32_t     OBIInt_t       a signed integer value
  float       double      OBIFloat_t     a floating value
- boolean     ?           OBIBool_t      a boolean true/false value
+ boolean     bool        OBIBool_t      a boolean true/false value
  char        char        OBIChar_t      a character
  index       size_t      OBIIdx_t       an index in a data structure
 =========   =========   ============   ==============================
diff --git a/doc/source/pistes.rst b/doc/source/pistes.rst
index 58388d6..aa981fd 100644
--- a/doc/source/pistes.rst
+++ b/doc/source/pistes.rst
@@ -10,8 +10,7 @@ Ce que l'on veut pouvoir faire
     * Gerer les valeurs manquantes
     * Modifier une colonne en cours d'ecriture (mmap)
     * Ajouter des valeurs a la fin du fichier d'une colonne en cours d'ecriture (mmap)
-    * 
-
+    
 
 ******
 Divers
@@ -19,3 +18,6 @@ Divers
 
 * Si l'ordre d'une colonne est change, elle est reecrite (pas d'index).
 * Utilisation de semaphores pour la lecture
+* Utilisation de tas pour l'indexation des chaines de caracteres. Chaque colonne dont 
+  le type est OBIStr_t est stockee dans 3 fichiers : un fichier contenant les chaines, un 
+  fichier contenant les index, et un fichier contenant le tas.