Gabriela, P. Calculus of fractions and homotopy theory / P. Gabriela nd M. Zisman - New York : Springer-Verlag, c 1967. - x, 168 p. : ill. ; 23 cm. - Ergebnisse der Mathematik und ihrer Grenzgebiete ; band 35. . Includes index. Bibliography : p. 163-164. 327 327 Subjects--Topical Terms: Homology theory.Homotopy theory.Mathematics. Dewey Class. No.: 517 / G114c