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Lua i Stíl Chicago (17ú heag.)FREDRICHS K O. PERTURBATION OF SPECTRA IN HELBERT SPACE. -: -, 1965.
Lua MLA (9ú heag.)FREDRICHS K O. PERTURBATION OF SPECTRA IN HELBERT SPACE. -, 1965.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.