Complex sentence: He played an integral role in the development of Canada's atomic age, and contributed greatly to Canadian aviation Oswald, Mary, They Led the Way, Canada's Aviation Hall of Fame, 1999.
Split into simpler sentences: He played an integral role in the development of Canada's atomic age. There is no doubt that he contributed greatly to Canadian aviation Oswald, Mary, They Led the Way, Canada's Aviation Hall of Fame, 1999.