Successful treatment of an equine preputial fibrosarcoma using 5-fluorouracil/evaluation of the treatment using quantitative PCNA and Ki67 (MIB 1) immunostaining. (case report)., Roels, S., Ducatelle R, van De Vijver B, and de Kruif A , Zentralbl Veterinarmed A, 1998 Dec, Volume 45, Issue 10, p.591-8, (1998)