diff --git a/relational/optimizations.py b/relational/optimizations.py
index c9ca62c..20b53ea 100644
--- a/relational/optimizations.py
+++ b/relational/optimizations.py
@@ -16,19 +16,18 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # 
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
-
-'''This module contains functions to perform various optimizations on the expression trees.
-The list general_optimizations contains pointers to general functions, so they can be called
-within a cycle.
-
-It is possible to add new general optimizations by adding the function in the list
-general_optimizations present in this module. And the optimization will be executed with the
-other ones when optimizing.
-
-A function will have one parameter, which is the root node of the tree describing the expression.
-The class used is defined in optimizer module.
-A function will have to return the number of changes performed on the tree.
-'''
+#
+# This module contains functions to perform various optimizations on the expression trees.
+# The list general_optimizations contains pointers to general functions, so they can be called
+# within a cycle.
+#
+# It is possible to add new general optimizations by adding the function in the list
+# general_optimizations present in this module. And the optimization will be executed with the
+# other ones when optimizing.
+#
+# A function will have one parameter, which is the root node of the tree describing the expression.
+# The class used is defined in optimizer module.
+# A function will have to return the number of changes performed on the tree.
 
 import optimizer
 import parser
diff --git a/relational/optimizer.py b/relational/optimizer.py
index bd38a9f..c96ff17 100644
--- a/relational/optimizer.py
+++ b/relational/optimizer.py
@@ -17,13 +17,13 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # 
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
-
-'''This module optimizes relational expressions into ones that require less time to be executed.
-
-expression: In all the functions expression can be either an UTF-8 encoded string, containing a valid
-relational query, or it can be a parse tree for a relational expression (ie: class parser.node).
-The functions will always return a string with the optimized query, but if a parse tree was provided,
-the parse tree itself will be modified accordingly.'''
+#
+# This module optimizes relational expressions into ones that require less time to be executed.
+#
+# expression: In all the functions expression can be either an UTF-8 encoded string, containing a valid
+# relational query, or it can be a parse tree for a relational expression (ie: class parser.node).
+# The functions will always return a string with the optimized query, but if a parse tree was provided,
+# the parse tree itself will be modified accordingly.
 
 import optimizations
 import parser
diff --git a/relational/parallel.py b/relational/parallel.py
index 88cc9a8..7ca43b5 100644
--- a/relational/parallel.py
+++ b/relational/parallel.py
@@ -16,8 +16,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # 
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
-
-'''This module offers capability of executing relational queries in parallel.'''
+# 
+# This module offers capability of executing relational queries in parallel.
 
 import optimizer
 import multiprocessing
diff --git a/relational/relation.py b/relational/relation.py
index 2a9b4b7..827d628 100644
--- a/relational/relation.py
+++ b/relational/relation.py
@@ -16,6 +16,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # 
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
+#
+# This module provides a classes to represent relations and to perform
+# relational operations on them.
 
 from rtypes import *
 import csv
diff --git a/relational/rtypes.py b/relational/rtypes.py
index 6a449e3..533b708 100644
--- a/relational/rtypes.py
+++ b/relational/rtypes.py
@@ -16,10 +16,10 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # 
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
-
-'''Custom types for relational algebra.
-Purpose of this module is having the isFloat function and
-implementing dates to use in selection.'''
+#
+# Custom types for relational algebra.
+# Purpose of this module is having the isFloat function and
+# implementing dates to use in selection.
 
 import datetime
 import re