W. GAERTNER & CO., 1905c Spectrometers and accessories : november 1905 / W. Gaertner & Co., astronomical, physical and physiological apparatus, 5347-5349 Lake Avenue, Chicago. – [S.l. : S.n.], 1905. – [2] p. : ill. ; 23 cm. Testo in inglese. Gaertner1905c 14 giugno 2017