Hi David,here are some pretty good bookstores that sell books in English and their address,telephone:
ATTICA
64 rue de la Folie Méricourt
75011 Paris, France
Telephone: +33 (0)1.49.29.27.27
THE BOOK CELLAR
23 rue Jean de Beauvais
75005 Paris
Telephone: +33 (0)1. 46.34.62.03
Fax: +33 (0)1. 46.34.81.13
BRENTANO'S
37 avenue de l'Opéra
75002 Paris
Telephone: +33 (0)1. 42.61.52.50
Fax: +33 (0)1. 42.61.07.61
GIBERT JEUNE
10 place St Michel
75006 Paris
Telephone: +33 (0)1.43.25.91.19
THE RED WHEELBARROW BOOKSTORE
22 rue St. Paul
75004 Paris
Tel & Fax +33 (0)1 48 04 75 08
Open 10-7 Monday - Saturday and Sunday afternoons
Hope you will find what you are looking for: