Applied Functional Analysis . By D. H. G RIFFEL . Ellis Horwood, 1981. 386 pp. £25 (hardback), £8.50 (paperback). Singular Perturbations and Asymptotics . Edited by R. E. M EYER and S. V. P ARTER . Academic Press, 1980. 409 pp. $22.00. Nonlinear Partial Differential Equations and their Applications. Collège de France Seminar . Vol. I. Edited by H. B REZIS and J. L. L IONS . Pitman, 1981. 388 pp. £11.75. Fluid Mechanics for Engineering Technology . By I RVING G RANET . Prentice-Hall Inc. 1981. 385 pp., £12.95. Hard cover.