Hi all, I'm a librarian in La Sorbonne library, geography department. Apologies for my english. We did in the end of 2016 the cataloging of a USGS serie, called with different names : "*30 x 60 minute series (topographic)*" (we have a few "planimetric" too) ; "*1:100 000-scale metric topographic map of...*", and follows the name of a town or a site ; "*30x60 minute quadrangle*". This maps were produced in the 70's and 80's by the USGS. The library have a great part of this serie for many years now. I'd like to make a brief history of this production, to inform my patrons and enhance this collection. I searched in the USGS website, but I found very few informations. Do you know if there is a (historical) review of this map serie somewhere online ? Or in a print document (and I'll try to get this document afterwards) ? Thank you ! Best regards, -- *Caroline Tourette* Tél. 01 44 32 14 61 Bibliothèque de géographie *Institut de Géographie* 191, rue Saint Jacques 75005 Paris