This and the other two stories in what Comic Book Database calls "Dr Strange Namor Hulk x-over" (because named arcs weren't the rage in 1970) are collected in "Day of the Defenders" in 2001! Also written by Roy Thomas.
Betty and Veronica have also been featured in the various other titles published by Archie Comics, and have each had their own title, usually for brief runs. Description from a1comix.com. I searched for this on bing.com/images