diff --git a/modules/purchase_trade/purchase.py b/modules/purchase_trade/purchase.py
index 56318b1..96b8981 100755
--- a/modules/purchase_trade/purchase.py
+++ b/modules/purchase_trade/purchase.py
@@ -530,6 +530,7 @@ class PriceComposition(ModelSQL,ModelView):
     price = fields.Numeric("Price")
 
 class Assay(ModelSQL, ModelView):
+    "Assay"
     __name__ = 'assay.assay'
 
     line = fields.Many2One('purchase.line',"Purchase Line")
@@ -558,6 +559,7 @@ class Assay(ModelSQL, ModelView):
     filename = fields.Char('Analysis')
 
 class AssayLine(ModelSQL, ModelView):
+    "Assay Line"
     __name__ = 'assay.line'
 
     assay = fields.Many2One('assay.assay', "Assay")