Here is Paul Copan’s article at the Gospel Coalition critiquing Presuppositional Apologetics:

http://thegospelcoalition.org/blogs/tgc/2012/03/12/questioning-presuppositionalism/

William Edgar’s Response can be found here at the Gospel Coalition:

http://thegospelcoalition.org/blogs/tgc/2012/03/11/fides-quaerens-intellectum-what-is-presuppositionalism/

Also James White responded to Paul Copan’s objections:

http://confessingbaptist.com/paul-copan-questions-presuppositionalism-james-white-responds-video/