Relative pronoun 'who' or 'which' when referring to article by authors' names
This depends entirely on the subject of your subordinate (relative) clause. 

If the authors are the subjects of the subordinate clause, use who. E.g. 


  Many postmodernists reacted angrily to the stunt pulled by Sokal (1996), who they felt had acted unethically in an effort to discredit their field. 


If the paper or text is the subject of the subordinate clause, use which. E.g.


  If you want to improve your mathematical writing, I recommend carefully examining Halmos (1974) which as a text manages the difficult feat of combining  scrupulous rigorous with broad accessibility.