Boundary-value problems / Ladis D. Kovach. Kovach, Ladis D. Boundary value problems. Differential equations, Linear. Differential equations, Partial. TA347.B69 K68 1984 515.35 19 KOB Includes index. Bibliography: p. 381. Reading, Mass. : Addison-Wesley Pub. Co., c1984. c1984. 1984 Text xii, 419 p. : eng