Gaya APA

Zawolek, M, W., Zadoks, J, C. (1989). A Phycical Theory of Focus Development in Plant Disease . Netherland: Agricultural University Wageningen.

Gaya MLA

Zawolek, M., W.., Zadoks, J., C.. "A Phycical Theory of Focus Development in Plant Disease". Netherland: Agricultural University Wageningen, 1989. Text.