Mekić, Cvijan, Grigorije Trifunović, Zorica Novaković, Radosav Vujić, and Dragan Romić. 2010. “The Rise of Proftability in Sheep Production by Out of Season Induction of Heat in Ewes”. Ekonomika Poljoprivrede 57 (Spec.num.2):117-22. https://ea.bg.ac.rs/index.php/EA/article/view/922.