1. A. V. Agafonov, Khim. i tekhnol. topliv i masel, No. 1 (1964).
2. D. H. Stormont, Oil and Gas J., Vol. 62, No. 14 (1964), p. 86.
3. P. W. Sherwood, Petroleum, Vol. 25, No. 4 (1962), p. 122.
4. D. H. Stormont, Oil and Gas J., Vol. 60, No. 7 (1962), p. 103.
5. D. H. Stormont and C. I. Lawrence, Oil and Gas J., Vol. 67, No. 47 (1963), p. 53.