There are some buildings in Belgrade that are built in the spirit of modernism of the 1930's, and this building (at 67 Kralja Aleksandra Boulevard) the faculty of law of the University of Belgrade is one of them (picture from stefan_serb).
The building was constructed in 1936–40 after a design by the architect Petar Bajalović further elaborated by Petar Anagnosti, an architect and university professor. It was conceived as an unornamented functional modern-style structure arranged on a rounded-triangular plan.
Bajalović saw the site as a corner location and therefore paid careful attention to both street facades creating an imposing entrance on the corner to provide a distinctive accent. The overall impression of dynamism stems from the interplay of alternate cubic and rounded forms, as well as from the sharp contrast between the calm facade surfaces and the monumental entrance portion.
The projecting portions of the street facades show prominent verticals in the form of pilasters between the windows.
The building has architectural and townscape value as a modernist corner structure which plays a significant role in the articulation of surrounding space and constitutes the starting point of a part of the complex of university buildings. Purposely designed to accommodate the Law School, one of the oldest institutions of higher education in Serbia, it also has cultural and historical value.(Text and pictures from Cultural properties of Belgrade)
Petar Bajalovic also designed the building of Drustvo Svetog Save in Belgrade (picture from Rascian on Skyscrapercity) and the Mihailo Petrovic Alas house (my post about it here)