Applewood Books [Publishers of Hardy Boys and Nancy Drew facsimile editions]
https://www.applewoodbooks.com/
Around the World with Nancy Drew
http://www.nancydrewworld.com/
The Hardy Boys Online
http://www.hardyboysonline.net/
The Hardy Boys Wiki
https://hardyboys.fandom.com/wiki/The_Hardy_Boys_Wiki
Hardy Detective Agency: Home of Hardy Boys Fan Fiction & Hardy Boys Information
Her Interactive: Home of Nancy Drew Mystery Games
https://www.herinteractive.com/
Nancy Drew
http://nancy-drew.mysterynet.com/
The Nancy Drew Sleuth Unofficial Website
http://www.nancydrewsleuth.com/
Papercutz [Home of the new Hardy Boys: Undercover Brothers and Nancy Drew: Girl Detective graphic novels]
https://papercutz.com/
SkyWarp’s Hardy Boys Casefiles Encyclopedia
https://www.hardyboyscasefiles.com/
The Stratemeyer Syndicate on Keeline.com
https://stratemeyer.org/