Volume 26 (1991)

Contributions

• J. Brunvoll, B. N. Cyvin, S. J. Cyvin: All-Benzenoid Systems: Distribution of K, the Number of Kekule Structures, in Benzenoid Hydrocarbons. XI, pp. 3-26
• S. J. Cyvin, J. Brunvoll, B. N. Cyvin: Forms of Benzenoid Chemical Isomers, pp. 27-62
• S. J. Cyvin, B. N. Cyvin, J. Brunvoll: Isomer Enumeration of Catafusenes, C_{4h+2}H_{2h+4} Benzenoid and Helicenic Hydrocarbons, pp. 63-86
• J. R. Dias: Strictly Pericondensed Benzenoid Isomers, pp. 87-93
• M. C. Donnamaria, A. N. Proto: Ionic Entropies for Thomas-Fermi-Amaldi Density Functional, pp. 95-109
• I. Gutman, E. C. Kirby: Three Theorems on Branching Graphs, pp. 111-122
• I. Gutman: McClelland-Type Approximations for Total pi-Electron Energy of Benzenoid Hydrocarbons, pp. 123-135
• P. John: Multilineare Aufzaehlpolynome fuer Anzahlen von Linearfaktoren in Katakondensierten Hexagonalen Systemen, pp. 137-154
• P. John : Eine zweite graphentheoretische Bemerkung zur Resonanztheorie benzenoider Kohlenwasserstoffe, pp. 155-170
• M. H. Klin, N. S. Zefirov: Group Theoretical Approach to the Investigation of Reaction Graphs for Highly Degenerate Rearrangements of Chemical Compounds. II. Fundamental Concepts, pp. 171-190
• R. Sheng, S. J. Cyvin, I. Gutman: Essentially Disconnected Benzenoids are Essentially Disconnected, pp. 191-203
• R. Sheng: On the Existence of Kekule Structures in Benzenoid Hydrocarbons, pp. 205-213
• V. A. Skorobogatov, E. V. Konstantinova: On the Correlation between the Molecular Information Topological and Mass-Spectra Indices of Organometallic Compounds, pp. 215-228
• F. Zhang, R. Chen, X. Guo, I. Gutman: Benzenoid Systems whose (x,y,z)-Invariants have x=1 and x=2, pp. 229-241
• F. Zhang, Y. Liu, R. Chen: A Note on Properties of Normal Benzenoids and Coronoids, pp. 243-246
• R. Sheng: The Number of Kekule Structures of Unbranched Catacondensed Benzenoid Systems and Primitive Coronoid Systems, pp. 247-253
• M. V. Diudea, I. E. Kacso: Molecular Topology. 9. Composition Rules for Some Topological Indices, pp. 255-269

Book Reviews

• H. R. Christen, Chemieunterricht - eine praxisorientierte Didaktik (Review by P. Pfeifer), pp. 273-275
• I. Gutman, S. J. Cyvin, Introduction to the Theory of Benzenoid Hydrocarbons (Review by P. E. John), pp. 277-279
• S. J. Cyvin, J. Brunvoll, B. N. Cyvin, Theory of Coronoid Hydrocarbons (Review by P. E. John, H. Sachs), pp. 281-282