1. Azukani P, Paoluzi P, Capurso L (1969) Endoscopy of the Colon. Proc. 1st Eur Congr Digestive Endoscopy, Prague 1968. Karger, Basel
2. Bond JH Jr, Levitt MD (1975) Factors affecting the concentration of combustible gases in the colon during colonoscopy. Gastroenterology 68:1445
3. Celestino A, Castillo F, Ayala L (1982) Colonoscopy in colon diseases. Am J Proctol Gastroenterol Colon Rectal Surg 33:18
4. Demling L, Classen M, Frühmorgen P (1974) Atlas der Enteroskopie. Springer, Berlin
5. Demling L, Frühmorgen P, Koch H, Rösch W (1976) Operative Endoskopie. Schattauer, Stuttgart