In addition to the "What is Strategy" article, there are several related (academic) journal articles. These articles are quite dense, but interesting nevertheless:

Evolution toward fit - http://www.management.wharton.upenn.edu/siggelkow/pdfs/Vangu...

Change in the presence of fit: The rise, the fall, and the renaissance of Liz Claiborne - http://knowledge.wharton.upenn.edu/papers/872.pdf