1. H. Boer andP. van Arkel, Chromatographia4, 300 (1971).
2. H. Boer andP. van Arkel, Hydrocarbon Processing51, No. 2 80 (1972).
3. H. Boer in “Gas Chromatography 1972”,S. G. Perry, ed. Applied Science Publishers Ltd., Barking 1973; p. 109.
4. H. Boer andW. J. Boersma unpublished results.
5. H. Boer andP. van Arkel, presentation at SAC Centenary Celebrations, London, July 1974; not appeared in print.