add a link in comment

rpg/core.py

@@ -31,7 +31,6 @@ AMINOACIDS = ["A", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N",
               "#", "*"]
 """All character accepted in a peptide."""
 
-
 AA_MASS_AVERAGE = {"*" : 0.0,
                    "A" : 71.0788,
                    "C" : 103.1388,
@@ -90,7 +89,9 @@ AA_MASS_MONO =  {"*" : 0.0,
                   "X" : 0.0,
                   "Z" : 0.0,
                   "#" : 0.0}
-""" Monoisotopic mass of all amino acids."""
+""" Monoisotopic mass of all amino acids.
+From https://proteomicsresource.washington.edu/protocols06/masses.php
+"""
 
 WATER_MASS = 18.01528
 """Mass of a water molecule."""