Citation - New York Gazette & Weekly Post Boy: 1761.05.07

NYGWPB.761.059
7 May 1761:42 (957 Supplement) 
This day are published and sold at the London Book Store,
over against the Golden Key in Hanover Square, by James
Rivington. 
1. The Young Lady's Magazine. . . [5 additional groups of
titles]
7. A Companion to the Theatre, containing all the histories
and novels, upon which all the most celebrated plays are
founded, together with the plan, character and incidents of
each.
. . . [8 more titles]