1. Boundary layer theory;Shlichting,1956
2. Regular degeneration and the boundary layer for linear small parameter differential equations;Vishik;Usp. mat. Nauk.,1957
3. Abstract of lectures on “The foundations of numerical mathematics”;Bakhvalov,1966
4. Shortcomings of the classical boundary layer theory;Chudov,1963
5. Asymptotic expansions of the error in the difference method of solving Cauchy's problems for systems of differential equations;Tikhonov;Zh. vȳchisl. Mat. mat. Fiz.,1962