If you could have only two CFA volumes...

I’m going to be traveling for two weeks in early April, and I figure I should be able to steal enough time to really pound away at two of the CFA volumes, which is all the incremental study material I’m willing to carry. I already read volume 2 and will review and do those questions before I leave. So what other two CFA volumes would be best to take with me?

Vols 3 & 4 seems logical to me.