It seem Del Rey took Ballantine's place since around 2000. And I notice in a 2012 Del Rey FR, "Ballantine" can still be found on the title page, even though the copyright page doesn't have it; whereas in a 2022 Del Rey FR it is not seen anywhere. Does Random House recently make Del Rey completely independent from Ballantine?
https://www.amazon.com/dp/0345339703?a ... collsguid-20&linkCode=osi
https://www.amazon.com/dp/0593500482?a ... collsguid-20&linkCode=osi