I am not familiar with the Structure of questions in this community, so please bear with me;
I am a Life sciences Graduate from 2015. After a career in Corporate, Currently I am Preparing to Apply for PhD in Universities abroad. As part of it, I am required to provide a certain number of references (Usually 2 or 3)
Is it Appropriate to approach my old college Professors for reference after a gap of 4 years ? What things should i Take into account if i am contacting them ?