APA (7th ed.) Citation

FREDRICHS K O. (1965). PERTURBATION OF SPECTRA IN HELBERT SPACE. -.

Chicago Style (17th ed.) Citation

FREDRICHS K O. PERTURBATION OF SPECTRA IN HELBERT SPACE. -: -, 1965.

MLA (9th ed.) Citation

FREDRICHS K O. PERTURBATION OF SPECTRA IN HELBERT SPACE. -, 1965.

Warning: These citations may not always be 100% accurate.