Frog Eye Gecko Classification

[raku_ubun]

Hi everyone, I am a newby here
I have recieved a pair of frog-eye gecko juvenile which are 5-6cm(svl) now caging together, both feed and behave well. It would me much appreciated if some expert can classify rather they are Teratoscincus przewalskii or Teratoscincus roborowskii:main_huh:
Can you tell me the method to classify them as well:main_robin:
Thank you:main_thumbsup:

 

[raku_ubun]

Two More photos posted from my pair of frog-eye gecko.
Check for the different body shape and pattern between them:main_thumbsup: