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. Boulanger EM (1902) Handboek voor gehuwden. NV Gebroeders Graauw, Amsterdam, Soerabaya
3. Hafferl A (1969) Lehrbuch der topographischen Anatomie. Springer, Berlin
4. Marani E (1996) Vorm en functie van het menselijk bekken. In: Urodynamica en Urine-incontinentie. Boerhaave Cie., Leiden, The Netherlands
5. Marani E (1993) The human pelvic floor: an introduction. In: Boerhaave cursus: pelvic floor. Boerhaave cie., Leiden, the Netherlands