diff --git a/doc/epp-doc.md b/doc/epp-doc.md
index a986ec85c..9aa7706fc 100644
--- a/doc/epp-doc.md
+++ b/doc/epp-doc.md
@@ -6,3 +6,6 @@ Introduction text here
 [[Contact related functions](epp/contact.md)]  
 [[Domain related functions](epp/domain.md)]  
 [[Keyrelay related functions](epp/keyrelay.md)]
+
+Please study official The Extensible Provisioning Protocol (EPP):
+http://en.wikipedia.org/wiki/Extensible_Provisioning_Protocol
diff --git a/doc/epp/contact.md b/doc/epp/contact.md
index 64f3fc056..dbe158efc 100644
--- a/doc/epp/contact.md
+++ b/doc/epp/contact.md
@@ -1,8 +1,12 @@
 ## Contact related functions
 
-Please study Cantact Mapping protocol:
+Please study official Cantact Mapping protocol:
 http://tools.ietf.org/html/rfc5733
 
+More info at http://en.wikipedia.org/wiki/Extensible_Provisioning_Protocol
+
+Contact Mapping protocol short version:
+
 ### Contact create
 
     Field name                 Min-max  Field description
diff --git a/doc/epp/domain.md b/doc/epp/domain.md
index 29ee2787e..c788ec142 100644
--- a/doc/epp/domain.md
+++ b/doc/epp/domain.md
@@ -1,5 +1,13 @@
 ## Domain related functions
 
+Please study official Domain Name Mapping protocol:
+http://tools.ietf.org/html/rfc5731
+
+More info at http://en.wikipedia.org/wiki/Extensible_Provisioning_Protocol
+
+Domain name mapping protocol short version:
+
+
 ### Domain create
 
     Field name                 Min-max  Field description