[1. Ceschini, P., and D. Cham: Beitr. Tabakforsch. 7 (1974) 294.]Search in Google Scholar
[2. Grob, K.: Beitr. Tabakforsch. 3 (1965) 243.]Search in Google Scholar
[3. Izard, C., and P. Testa: Annales SEITA 6-1968, 121.]Search in Google Scholar
[4. Wynder, E. L., and D. Hoffmann: Tobacco and tobacco smoke; Academic Press, New York - London, 1967.]Search in Google Scholar