Hey,
I know the previous posters have answered your question, but just to make it all clear:
Our third edition books refer to the OG11 and the Verbal and Quant review 1st editions
Our fourth edition books refer to the OG12 and the Verbal and Quant review 1st editions
Our 4.1 edition books refer to the OG12 and the Verbal and Quant review 2nd editions.
You can find the conversion documents here:
https://www.manhattangmat.com/fourth-ed-info.cfmHope that's helpful!
Best,
Caitlin Clay
Student Services Associate
Manhattan GMAT