Calculus of vector functions, by R.H. Crowell and R.E. Williamson, with the assistance of H. Mirkil. Crowell, Richard H. Williamson, Richard E., joint author. Vector analysis. QA261 .C8 517 19 CRC Englewood Cliffs, N.J., Prentice-Hall, 1962. 1962. 1962 Text x, 484 p. eng