THE GAERTNER SCIENTIFIC CORPORATION, 1940

Gaertner chronographs and time standards : tape chronographs, drum chronographs, tuning forks, regulator clocks : Catalog B2 / The Gaertner Scientific Corporation, 1201 Wrightwood Avenue, Chicago, U.S.A. – [S.l. : S.n.], c1940. – 24 p. : ill. ; 28 cm.
Testo in inglese.