Strategic management is concerned with the match between the internal capabilities of the company and its external environment according to one school of thought. Although there is much disagreement of substance among those who write about strategic management, most agree this is the issue. Choose any three of these Gurus (example: Chandler, Igor Ansoff, Porter, Drucker, Mintzberg, Strickland et al) and describe their contributions and in your opinion, are they still relevant in today's turbulent business scenario?