Besjes, J. G. Singular perturbation problems for linear elliptic differential operators of arbitrary order. III: Counterexamples. (English) Zbl 0346.35011 Nieuw Arch. Wiskd., III. Ser. 25, 1-39 (1977). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page MSC: 35B25 Singular perturbations in context of PDEs 35G15 Boundary value problems for linear higher-order PDEs 35B45 A priori estimates in context of PDEs PDF BibTeX XML Cite \textit{J. G. Besjes}, Nieuw Arch. Wiskd., III. Ser. 25, 1--39 (1977; Zbl 0346.35011)