C. Heber D. (Feb 1911). „Methods of Silvering Mirrors“. Publications of the Astronomical Society of the Pacific. 23 (135): 15–19. Bibcode:1911PASP...23...13C. doi:10.1086/122040.
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C. Heber D. (Feb 1911). „Methods of Silvering Mirrors“. Publications of the Astronomical Society of the Pacific. 23 (135): 15–19. Bibcode:1911PASP...23...13C. doi:10.1086/122040.