1. Holstein, A. F. Morphological evidence for the involution of spermatogenesis during senescence in Reproductive Biology and Medicine (ed. Holstein, A. F.) 66–77 (Diesbach Verlag, 1989).
2. Regadera, J., Nistal, M. & Paniagua, R. Testis, epididymis, and spermatic cord in elderly men. Correlation of angiographic and histologic studies with systemic arteriosclerosis. Arch Pathol Lab Med 109, 663–667 (1985).
3. Müller, I. Architectonic of the canals and capillaries of rat testes. Z Zellforsch Mikrosk Anat 45, 522–537 (1957).
4. Hundeiker, M. Die Capillaren im Hodenparenchym. Arch Klin Exp Dermatol 239, 426–435 (1971).
5. Kormano, M. & Suoranta, H. Microvascular organization of the adult human testis. Anat Rec 170, 31–39 (1971).