https://www.theatlantic.com/entertainment/archive/2015/05/hardy-boys-nancy-drew-ghostwriters/394022/
Eighty-five years have passed since readers first encountered both the Hardy Boys and their teen-detective counterpart, Nancy Drew, yet new books continue to be released several times a year. The novels bear the same pseudonyms as the originals: Franklin W. Dixon and Carolyn Keene. A few things have changed, though—characters listen to MP3 players and reference science-fiction movies, and Hardy Boys chapters (oddly) alternate between the first-person perspectives of Frank and Joe. But the main modern achievement of the series is simply that it continues to exist.