JAWAD, L.A. Eye lens diameter and age determination in the tilapia fish, Tilapia zilli. In Biologia. Section A. Section B. Section C, Botany. Zoology. Cellular and molecular biology. ISSN 0006-3088. ISSN 1335-6372. ISSN 1335-6380. ISSN 1335-6399, 2001, roč. 56, č. 5, s. 573-575.