[1] He published and edited books "Kelsen and Marx," "Foundations of the Legal System of SFR Yugoslavia," and "The Philosophy of Law.

"[2] From 1972, Grebo lectured at the Faculty of Law in Sarajevo, becoming a professor in January 1991.

[1][4] In 2017, he signed the Declaration on the Common Language of the Croats, Serbs, Bosniaks and Montenegrins.

He was also director of the Center for Interdisciplinary Postgraduate Studies of the University of Sarajevo.

He also served as the chief of the Department of the State and International Public Law.