sponsored by the United Nations Institute for Training and Research , and Petroleos de Venezuela, S.A., in cooperation with the United States Department of Energy, and Alberta Oil Sands Technology and Research Authority ; R. F. Meyer, J. C. Wynn and J. C. Olson, editorsMining Informational Services, McGraw-Hillc1984
sponsored by the United Nations Institute for Training and Research (UNITAR), Alberta (Canada) Oil Sands Technology and Research Authority (AOSTRA), and the United States Department of Energy, in cooperation with the Government of Venezuela ... [et al.] ; R. F. Meyer and C. T. Steele, editors, J. C. Olson, assistant editorMining Informational Services, McGraw-Hillc1981