Tom Swift And His Atomic Earth Blaster (see here) and Citizen Of The Galaxy (see here). I recognize the latter as a Heinlein Scribner Juvenile but the Tom Swift series is news to me although the name was slightly familiar. I was eleven in 1960.
Sf writers acknowledge their antecedents by having their characters refer to them. We recognize a literary lineage from Heinlein via Poul Anderson to SM Stirling. Tom Swift sounds like the kind of stuff that I would have read in the late '50s if I had known of it then. I did read Starman Jones in a large format illustrated omnibus volume of juvenile novels by different authors but did not notice any of the authors' name. Next, I read Orphans Of The Sky by Heinlein in the '60s, then found a copy of Starman Jones and realized that it was by the same author. My first Anderson story, read some time in the 60's, was "The Game of Glory."
We frequently hear of entire juvenile series that we never knew of at the right time.