Published by Duke University Press since its inception in 1935, the Duke Mathematical Journal is one of the world's leading mathematical journals. Without specializing in a small number of subject areas, it emphasizes the most active and influential areas of current mathematics.

### Volume 42, Number 2

#### Publication Date: June 1975

A torsion version of the Chase-Rosenberg exact sequence

Gerald S. Garfinkel; 195-210

Structural instability and extensions of Riemann surfaces

H. Renggli; 211-224

A direct proof of the Kirillov character formula for nilpotent groups

Ronald L. Lipsman; 225-229

On the projection of $L\sp{2}(D)$ into $H(D)$

Mario Landucci; 231-237

An auxiliary result in the theory of transcendental numbers II

P. L. Cijsouw and R. Tijdeman; 239-247

On the simultaneous approximation of certain numbers

P. L. Cijsouw; 249-257

Approximation from the space of compact operators and other $M$-ideals

Richard Holmes, Bruce Scranton and Joseph Ward; 259-269

Irreducible divisors in domains of finite character

Anne Grams and Hoyt Warner; 271-284

On extreme points and support points for some families of univalent functions

W. E. Kirwan and G. Schober; 285-296

The action of free $G$-bordism on $G$-bordism

R. Paul Beem; 297-305

Transitive horocycles for Fuchsian groups

Peter J. Nicholls; 307-312

On prime ideals $p\subset P\cap Q$

S. McAdam and L. J. Ratliff, Jr.; 313-319

Isometries of $H\sp{\infty}$

P. R. Ahern and Robert Schneider; 321-326

On a problem of Julia

H. Alexander; 327-332

Exponential sums over finite simple Jordan algebras and finite simple associative algebras

Liang-Chi Tsao; 333-345

An integral formula for holomorphic functions on strictly pseudoconvex hypersurfaces

Edgar Lee Stout; 347-356

On free nilmanifolds and their associated non compact solvmanifolds

L. Auslander and R. H. Szczarba; 357-369

Schiffer’s interior variation and quasiconformal mapping

Frederick P. Gardiner; 371-380

Correction: The generalized geodesic flow

Leon W. Green; 381