The Illinois Journal of Mathematics was founded in 1957 by R. Baer, J.L. Doob, A. Taub, G. Whitehead, and O. Zariski. The inaugural volume featured papers of many of the world's leading figures in the key areas of mathematics at the time. Since its inception, the IJM has published many influential papers, most notably the proof of the Four Color Conjecture by K. Appel and W. Haken. Distinguished researchers such as J. Bourgain, A. Calderon, S.S. Chern, H. Kesten, and K. Uhlenbeck have served as Editors of the IJM.

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### Volume 19, Issue 3

#### Publication Date: September 1975

Frontmatter

Height functions on surfaces with three critical points

Thomas Banchoff and Floris Takens; 325-335

Algebraic vector bundles over the $l$-hole torus

Joseph M. Cavanaugh; 336-343

On finite linear groups of degree 16

Harvey I. Blau; 344-353

Piecewise linear embeddings of manifolds

Kenneth C. Millett; 354-369

Decompositions of finitely additive vector measures generated by bands of finitely additive scalar measures

W. M. Bogdanowicz and R. A. Oberle; 370-377

Certain quotient spaces are countably separated

Robert R. Kallman; 378-388

Essentially $(G_{1})$ operators and essentially convexoid operators on Hilbert space

Glenn R. Luecke; 389-399

Some conditions for uniform $H$-convexity

Barnet M. Weinstock; 400-404

Cubic forms in Gaussian variables

F. Alberto Grünbaum; 405-411

Generalization of a theorem of Hayman to $R^{n}$

M. N. M. Talpur; 412-423

Isometries induced by composition operators and invariant subspaces

Arthur Lubin; 424-427

On the hierarchy of W. Krieger

A. Connes; 428-432

A characterization of projective spaces in terms of $h$-enclosability

P. Antonelli and K. Varadarajan; 433-439

Embeddings of topological manifolds

Erik Kjaer Pedersen; 440-447

A formula for Ramanujan's $\tau$-function

Douglas Niebur; 448-449

A lattice property of post's simple set

Paul F. Cohen and Carl G. Jockusch; 450-453

$L^{1}$-algebras on semigroups

George Akst; 454-466

Modules with waists

M. Auslander, E. L. Green and I. Reiten; 467-478

Sur la non factorisation des elements de l'espace de Hardy $H^{1}(U^{2})$

Jean-Pierre Rosay; 479-482

Backmatter