Sven J. Cyvin Bjorg N. Cyvin Ivan Gutman   | Topological properties of benzenoid systems. XLII. Number of Kekulé structures of more peri-condensed molecules  | 5 | 
Ivan Gutman   Zoran Marković   | Topological properties of benzenoid systems. XLIa. Carbon-carbon bond types and total electron energy of benzenoid hydrocarbons  | 21 | 
| Vitko M. Šorić  | Distribution and characteristics of Phoxinus phoxinus in some waters of Yugoslavia  | 27  | 
Miroslav Vučković Nikola Rosić  | On a linear differential equation  | 37 | 
| Stamena Radotić | Das verhaltnis der produktion des ober- und unterirdschen teiles von biomase der art Chrysopogon gryllus Trin. auf dem kalksteinigen und serpentin geologischen grunde  | 45 | 
Vukota Babović Vladimir Ristić   | Soldner's formula: the premature curiosity or the lost chance  | 53 | 
Mladen Karaman Spasenija Karaman   | Urnatella gracilis leidy (Entoprocta, Urnatellidae) a new species in the hydrofauna SR Serbia  | 65  | 
Petar Marković Dragoslav Nikezić  Sava S. Milojević Dragana Kostić   | Some results of investigation of the radiological situation of the Gruža lake and its contributors  | 73 |