Journal of Combinatorial Theory, Series A, Volume 20

Volume 20, Number 1, January 1976

Peter Frankl: On Sperner Families Satisfying an Additional Condition. 1-11
T. D. Parsons: Ramsey Graphs and Block Designs. 12-19
Clement W. H. Lam: Nth Power Residue Addition Sets. 20-33
James P. Conlan: Derived Tilings. 34-40
Curtis Greene, Daniel J. Kleitman: The Structure of Sperner k-Families. 41-68
Curtis Greene: Some Partitions Associated with a Partially Ordered Set. 69-79
Curtis Greene, Daniel J. Kleitman: Strong Versions of Sperner's Theorem. 80-88
Daniel J. Kleitman: Some New Results on the Littlewood-Offord Problem. 89-113
William T. Trotter: A Generalization of Hiraguchi's: Inequality for Posets. 114-123
Masahiko Sato: On Formal Fractions Associated with the Symmetric Groups. 124-131

Volume 20, Number 2, March 1976

John D. Fulton: PBIB Designs with m Associate Classes Induced by Full Rank Matrices Modulo p^m. 133-144
B. R. McDonald: Simple Subrings of Matrix Rings over Finite Fields. 145-153
K. Kjeldsen: On the Cycle Structure of a Set of Nonlinear Shift Registers with Symmetric Feedback Functions. 154-169
Patrick Scott Mara: Triangulations for the Cube. 170-177
Karsten Steffens: Ergebnisse aus der Transversalentheorie. I. 178-201
Karsten Steffens: Ergebnisse aus der Transversalentheorie. II. 202-229
Philippe Delsarte: Association Schemes and t-Designs in Regular Semilattices. 230-243
Thomas Zaslavsky: Maximal Dissections of a Simplex. 244-257
Surya Prakash Rao Hebbare, G. A. Patwardhan: On Some Constructions of Modular Hadamard Matrices. 258-263

Volume 20, Number 3, May 1976

A.-A. A. Jucys: The Number of Distinct Latin Squares as a Group-Theoretical Constant. 265-272
Michael J. Klass: A Generalization of Burnside's Combinatorial Lemma. 273-278
M. Cates, Paul Erdös, N. Hindman, Bruce Rothschild: Partition Theorems for Subsets of Vector Spaces. 279-291
F. M. Dekking: On Repetitions of Blocks in Binary Sequences. 292-299
O. S. Rothaus: On "Bent" Functions. 300-305
Michel Deza: Matrices Dont Deux Lignes Quelconque Coïncident dans un Nombre Donne de Positions Communes. 306-318
Alphonse Baartmans, Kenneth J. Danhof: On Representing Block Designs in Terms of Their Automorphisms. 319-326
Robert W. Shannon: A Lower Bound on the Number of Cells in Arrangements of Hyperplanes. 327-335
Richard P. Stanley: Binomial Posets, Möbius Inversion, and Permutation Enumeration. 336-356
J. G. Kingston: Comparison of Scoring Systems in Two-Sided Competitions. 357-362
D. Craggs: On the No-Three-in-Line Problem. 363-364
N. J. Patterson: A Four-Dimensional Kerdock Set over GF(3). 365-366
Daniel I. A. Cohen: An Explanation of the First Digit Phenomenon. 367-370
Frank Harary, Allen J. Schwenk: On Tactical Configurations with No Four-Cycles. 371-374
Louis W. Shapiro: A Short Proof of an Identity of Touchard's Concerning Catalan Numbers. 375-376
Jay Rosen: The Number of Product-Weighted Lead Codes for Ballots and Its Relation to the Ursell Functions of the Linear Ising Model. 377-384
Leslie E. Shader: All Right Triangles Are Ramsey in E². 385-389
Daniel J. Kleitman: Extremal Properties of Collections of Subsets Containing No Two Sets and Their Union. 390-392
Kevin T. Phelps: Some Sufficient Conditions for a Steiner Triple System to Be a Derived Triple System. 393-397
B. L. Rothschild: Characterizing k-Flats in Geometric Designs. 398-403