1. Literature has been grouped in reference lists of several chapters in those cases where arguments are difficult to entangle or published over several articles or books. In cases of citation the article or book involved is indicated by the reference number together with a capital Arabic letter.
2. Moonen WA (1969) Iets over de geschiedenis van de catheter. Ned Tijdschr Geneeskd 113:1201–1204
3. Cools HJM (1991) Catheter beleid in verpleeghuizen. Glaxo BV ISBN: 90-71941-17-5
4. Barsanti JA, Blue J, Edmunds J (1985) Urinary tract infection due to indwelling bladder catheters in dogs and cats. J Am Vet Med Assoc 187:384–388
5. Warren JW (1987) Catheter-associated urinary tract infections. Infect Dis Clin North Am 1:823–854