Chafin, F., 2001: Get the most out of modifiers. Medical Economics 78(15): 18, 20-18, 20
Bollen, M., 1996: GPs and breast cancer. Australian Family Physician 25(11): 1665-1666
Groner, G., 1977: Cactus culture in glass bed boxes. Gartenpraxis 9 421-424