1. U. S. Patent 4097370, June 27, 1978.
2. U. S. Patent 4113603, September 12, 1978.
3. and “Preprints”, Division of Petroleum Chemistry, Inc., American Chemical Society, New York, August 1972 Volume 17, No. 4, p. F 38.
4. Detailed high resolution gas chromatography-mass spectrometry analysis of a pyrolysis naphtha