Public Petroleum Association of Canada, Laxer, J., & Martin, A. 1. (1976). The Big tough expensive job: Imperial Oil and the Canadian economy. Press Porcepic.
Lua i Stíl Chicago (17ú heag.)Public Petroleum Association of Canada, James Laxer, agus Anne 1951 Martin. The Big Tough Expensive Job: Imperial Oil and the Canadian Economy. [Erin, Ont.]: Press Porcepic, 1976.
Lua MLA (9ú heag.)Public Petroleum Association of Canada, et al. The Big Tough Expensive Job: Imperial Oil and the Canadian Economy. Press Porcepic, 1976.
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