KEUFFEL & ESSER CO.
K & E slide rules and calculating instruments. NM: additions & revisions.
KEUFFEL & ESSER CO. K & E slide rules and calculating instruments. NM: additions & revisions. © 8Aug44; AA462682. Keuffel & Esser Co. (PWH); 17Sep71; R512886.
Keuffel & Esser Co.|PWH