1. Van der Waaij D: The colonization resistance of the digestive tract in experimental animals and its consequences for infection prevention, acquisition of new bacteria and the prevention of spread of bacteria between cage mates. In: Van der Waaij D, Verhoef J (eds). New criteria for antimicrobial therapy: maintenance of digestive tract colonization. Amsterdam Excerpta Medica (ICS 477), 1979.
2. Van der Waaij D: The colonization resistance of the digestive tract with special emphasis on the oropharynx. In: Van Furth R (ed). Developments in antibiotic treatment of respiratory infections. The Hague, Martinus Nijhoff, 1981.
3. Buck AC, Cooke EM: The fate of ingested Pseudomonas aeruginosa in normal persons. J Med Microbiol 2:521–525, 1969.
4. Cooke EM,Hettiaratchy ICT, Buck AC: Fate of ingested Escherichia coli in normal persons. J Med Microbiol 5:361–369, 1972.
5. Van der Waaij D, Berghuis-de Vries JM, Lekkerkerk-van der Wees JEC: Colonization resistance of the digestive tract in conventional and antibiotic treated mice. J Hyg 69:405–411, 1971.