Showalter, R. E. (1977). Hilbert space methods for partial differential equations. Pitman.
Lua i Stíl Chicago (17ú heag.)Showalter, R. E. Hilbert Space Methods for Partial Differential Equations. London: Pitman, 1977.
Lua MLA (9ú heag.)Showalter, R. E. Hilbert Space Methods for Partial Differential Equations. Pitman, 1977.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.