(Did you mean a book, apa or conventions in Florida, Massachusetts, or London?)

Necronomicon Providence seems to be a Lovecraft-oriented cross between a fannish convention and a mundane conference held in Providence, RI. It is sponsored by the Lovecraft Arts & Sciences Council.

Convention Dates GoHs
Necronomicon Providence 2013 August 23-25, 2013 S.T. Joshi, Robert Price, Wilum H. Pugmire, Stuart Gordon, Laird Barron, Caitlin R. Kiernan, Paul Komoda, Sandy Petersen
Necronomicon Providence 2015 August 20-23, 2015 Ramsey Campbell, John Coulthart, Lois H. Gresh, Stephen Jones, Leslie Klinger, Silvia Moreno-Garcia, Robert Price, Ann K. Schwader, and Donald Burleson
Necronomicon Providence 2017 August 17-20, 2017 Ellen Datlow, Richard Stanley, John Jude Palencar, poet Donald Sidney-Fryer, Steve Mariconda, Kij Johnson, Stephen Graham Jones, Nnedi Okorafor, and Peter Straub
Necronomicon Providence 2019 August 22-25, 2019
Wikipedia Fanac File770
Concatenation Fanlore (IA) Website