Relationship between strong and weak axioms of revealed preference
The only journal that published it is behind a paywall: 
http://www.jstor.org/stable/2296210?seq=1#page_scan_tab_contents but check your school library access for it. 

The proof is pretty complicated and is based on an induction argument. When I've tried to link SARP and WARP, I've only ever found references to his paper.