The Hardy Boys

Working my way through the A’s in the Encyclopedia of Science Fiction last night before going to bed, I came across an entry for Harriet Adams which took me by surprise. She was the editor of a publishing syndicate beginning in the 1930s. Quoting from the Encyclopedia, here’s what surprised me:

Under a variety of house names, including Carolyn Keene, Franklin W. Dixon and Laura Lee Hope, she was herself responsible for writing approximately 170 of the Stratemeyer Syndicate novels about the Bobbsey Twins, the Hardy Boys, Nancy Drew and others.

I read several of the Hardy Boys mysteries when I was a kid, and until I read that passage last night, I would never have guessed that Dixon was a house name and that those books were written by a woman. (And that she also wrote the Nancy Drew books.)

Is this fairly common knowledge?