I am a postgraduate student in mathematics (if it matters) who is now also applying for doctoral positions, some of which require three references.
It was a logical enough decision to select my academic advisor and my thesis supervisor to be my first two references, and they gladly accepted. However, attaining a third reference is proving much trickier.
There was no immediate choice, so I decided to contact a lecturer of mine whose course I am currently following with whom I have quite a good relationship (as the class size is also small). Much to my disappointment, he wrote back to me only to decline and say that he does not know me nor my academic achievements well enough to provide a serious reference for me.
Now I am at a loss, because the only people who really know of my academic achievements are the two people who already agreed to be references for me; so where do I go from here?