1. Cottrell, J. H., “Development of an Anhydrous Process for Oil Sand Extraction”. “Athabasca Oil Sands: A Collection of Papers Presented to K. A. Clark on his 75th Birthday”, M. A. Carrigry (ed.) Research Council of Alberta, Edmonton, Canada (Oct. 1963).
2. Anon., “Ultrasonics for Oil Sands”, Oil Week, (Feb. 10, 1976).
3. Agitated vessel particle-liquid mass transfer: A comparison between theories and data
4. The solubility of asphaltenes in hydrocarbon solvents