Here is a nice, albeit dated, diagram taken from the following link, also worth reading:
http://fieldherping.eu/Forum/viewtopic.php?f=25&t=995&start=20
A = V. a. ammodytes - NW Bulgaria
B = V. a. montandoni - Romanian Dobrudja
C = V. a. meridionalis - Greece
D = V. a. transcaucasiana - Georgia
R = Rostral
SR = Suprarostral