correct sentence

It is correctly punctuated. If John Smith is the only doctoral student supervised by the recipient, then you perhaps should use "the". If he is one of a number of doctoral students supervised by the recipient, then "a" might be better, although in fact either is OK.

Many thanks, Contrex.

This should be tidied up.



Preposition needed before "this"...

also resolution of ambiguity required...

has recommended that I apply for this position. (?)

has recommended that I be appointed to this position (?)

has kindly agreed to provide me with a reference (?)

Many thanks, Contrex.

I agree with what you said.