REFERENCES
- Allen CJ (1981): To be Quechua: the symbolism of coca chewing in highland Peru. Am Ethnol 8: 157–168.
- Barz W, Koster J (1981): Turnover and degradation of sec-ondary (natural) products. In: Stumpf PK, Conn EE, Eds., The Biochemistry of Plants: a Comprehensive Treatise. Vol. 7. New York, Academic Press, pp.35-84.
- Henry TA (1949): The Plant Alkaloids, 4th ed. London, Churchill.
- Jeffs PW, Archie WC, Hawks RL, Farrier DS (1971): Biosyn-thesis of mesembrine and related alkaloids. The amino acid precursors. J Am Chem Soc 93: 3752–3758.
- Laidler PW (1928): The magic medicine of the Hottentots. S Afr J Sci 25: 433–447.
- Martin NH, Rosenthal D, Jeffs PW (1976): Mass spectra of Sceletium alkaloids. Org Mass Spectrometry 2: 1–19.
- Meiring 1(1898): Notes on some experiments with the active principle of Mesembryanthemum tortusum. Trans S Afr Philos Soc 9: 48–50.
- Smith MT, Crouch NR, Gericke N, Hirst M (1996): Psy-choactive constituents of the genus Sceletium N.E.Br. and other Mesembryanthemaceae: a review. J Ethnopharma-col 50: 119–130.
- Waterhouse G (1932): Simon van der Stel's Journal of his Expedition to Namaqualand 1685-6. London, Longmans, Green and Co.
- Waterhouse G, De Wet GC, Pheiffer RH (1979): Simon van der Stel's Journey to Namaqualand in 1685. Cape Town, Human and Rousseau.
- Watt JM, Breyer-Brandwijk MG (1962): The Medicinal and Poisonous Plants of Southern and Eastern Africa 2nd ed. London, Livingstone.
- Zwicky E (1914): Uber Channa, em n Genussmittel der Hot-tentotten (Mesembrianthemum expansum L. und tortuo-sum L.). Wurde ems Doktors der Naturwissenschaften. Eidgenossischen Technischen Hochschule in Zurich.