1 Cyclobutane-physical properties and theoretical studies (Kenneth B. Wiberg). 2 Antiaromaticity and aromaticity in carbocyclic four-membered rings (M. Eckert-Maksic and Z. B. Maksic). 3 Stereochemical aspects-conformation and configuration (Ulf Berg). 4 Thermochemistry of cyclobutane and its derivatives (Joel F. Liebman and Suzanne W. Slayden). 5 Acidity and basicity of cyclobutanes (Esther Quintanilla, Juan Z. Davalos, Jos-e Luis M. Abboud and Ibon Alkorta). 6 NMR spectroscopy of cyclobutanes (Peter Rudolf Seidl and Jacques Fernandes Dias). 7 Mass spectrometry and gas-phase ion chemistry of cyclobutanes (Dietmar Kuck). 8 Synthesis of cyclobutanes (E. Lee-Ruff). 9 The application of cyclobutane derivatives in organic synthesis (Nan-Yan Fu, Siu-Hin Chan and Henry N. C. Wong). 10 Structural effects of the cyclobutyl group on reactivity and properties (Marvin Charton). 11 Rearrangements of cyclobutanes (J. M. Tanko). 12 Cyclobutyl, cyclobutyl-substituted and related carbocations (Hans-Ullrich Siehl). 13 Cation radicals in the synthesis and reactions of cyclobutanes (Nathan L. Bauld). 14 Highly unsaturated cyclobutane derivatives (Richard P. Johnson). 15 Cyclobutarenes (Amnon Stanger). 16 Organometallic derivatives (Holger Butenschon) 17 Photochemistry of cyclobutanes: Synthesis and reactivity (William M. Horspool). 18 Solvent-free photosynthesis of cyclobutanes: Photodimerization of crystalline olefins (Arunkumar Natarajan and V. Ramamurthy). 19 Chemistry of cubane and other prismanes (A. Bashir-Hashemi and Hiroyuki Higuchi). 20 Bicyclo[2.1.0]pentanes and bicyclo[2.2.0]hexanes (Barry K. Carpenter). 21 Fluorinated cyclobutanes and their derivatives (David M. Lemal and Xudong Chen). 22 Cyclobutane pyrimidine dimers as UV-induced DNA lesions (Marcus G. Friedel, Johannes Gierlich and Thomas Carell). 23 Cubanes, fenestranes, ladderanes, prismanes, staffanes and other oligocyclobutanoids (Henning Hopf, Joel F. Liebman and H. Mark Perks). Author index. Subject index.