Volume 86 (2021) number 1

• N. Dehgardi, J. B. Liu: Lanzhou Index of Trees with Fixed Maximum Degree, pp. 3-10
• I. Gutman: Geometric Approach to Degree-Based Topological Indices: Sombor Indices, pp. 11-16
• M. Enteshari, B. Taeri: Extremal Zagreb Indices of Graphs of Order n with p Pendent Vertices, pp. 17-28
• Y. Jiang, X. Chen, W. Lin: A Note on Chemical Trees with Maximal Inverse Sum Indeg Index, pp. 29-38
• T. Alraqad, A. Ali, H. Saber: Solution of an Open Problem Concerning the Augmented Zagreb Index and Chromatic Number of Graphs, pp. 39-48
• R. Hoshikawa, K. Waki, H. Sakiyama: Enumeration of Conformers for Tetrahedral [MX_4-n(AB)_n] Complexes (n = 1-4), pp. 49-58
• R. M. Nemba, T. Makon: Bipartite Enumeration of Substituted Dodecahedrane Derivatives and Heteroanalogues. I., pp. 59-83
• R. M. Nemba: The Denumerants of Icosahedral Group for Symmetry Itemized Enumeration of Coisomeric Dodecahedrane Derivatives and Heteroanalogues. II., pp. 85-120
• B. H. He, H. A. Witek: Clar Theory for Hexagonal Benzenoids with Corner Defects, pp. 121-140
• B. H. He, J. Langner, R. Podeszwa, H. A. Witek: Can the John-Sachs Theorem be Extended to Clar Covers?, pp. 141-163
• H. A. Witek, R. Podeszwa, J. Langner: Closed-Form Formulas for Zhang-Zhang Polynomials of Hexagonal Graphene Flakes O(k, m, n) with k, m = 1-7 and Arbitrary n, pp. 165-194
• W. Yan, S. Li: Relation Between the Gutman Index of a Tree and Matchings, pp. 195-205