Robbins Path can mean the textbook Robbins and Cotran Pathologic Basis of Disease, or the question book, Robbins and Cotran Review of Pathology. The one with Cotran is just the 2nd edition of the same book. I'm not sure how much is different but if you cannot get a hold of the 2nd edition I'm sure the 1st is fine. Since there is so much confusion with Robbins, how about the following terminology:
Big Robbins (Pathologic Basis of Disease)
Medium Robbins (Robbins Basic Pathology)
Small Robbins (Pocket companion)
Robbins question book