The First Boundary Value Problem for εΔu + A(x, y)u x + B(x, y)u y + C(x, y)u = D(x, y) for Small ε

Asymptotic solution of boundary value problems for the differential equation ΔU+λ∂∂xU=λf(x,y)

1944 • 26 citations

Zur Theorie der Differentialgleichungen

1928 • 4 citations