Calculus of several variables / Serge Lang. Lang, Serge, 1927-2005. Calculus. Functions of several real variables. QA303 .L256 1987 515.84 19 L269c Includes index. New York : Springer-Verlag, c1987. c1987. 1987 Text xii, 479 p. : http://www.loc.gov/catdir/enhancements/fy0814/86017724-d.html http://www.loc.gov/catdir/enhancements/fy0814/86017724-t.html eng Undergraduate texts in mathematics