Annals of Combinatorics, Volume 1, No. 3, 1997 A.M. Bigatti and L. Robbiano Borel Sets and Sectional Matrices Ann. Combin. 1 (1997) 197-213. Y.M. Chee, C.J. Colbourn, and A.C.H. Ling Weakly Union-free Twofold Triple Systems Ann. Combin. 1 (1997) 215-225. D.L. Kreher, D.R. Stinson, and L. Zhu On the Maximum Number of Fixed Points in Automorphisms of Prime Order of 2-(v,k,1) Designs Ann. Combin. 1 (1997) 227-243. J.A. Larson and W.J. Mitchell On a Problem of Erdös and Rado Ann. Combin. 1 (1997) 245-252. C.M. Lopez Chip Firing and the Tutte Polynomial Ann. Combin. 1 (1997) 253-259 P. McMullen and E. Schulte Flat Regular Polytopes Ann. Combin. 1 (1997) 261-278. K. Wahlgren and Z.-X. Wan Studies on the Squaring Construction Ann. Combin. 1 (1997) 279-295.