W. GAERTNER & CO., 1904

Instruments of precision, laboratory apparatus, astronomical instruments : Circular M-L-A : 1904 / W. Gaertner & Co., astronomical, physical and physiological apparatus, 5347-5349 Lake Avenue, Chicago. – [S.l. : S.n.], c1904. – 69 p. : ill. : 23 cm.
Testo in inglese.