This how the book cover looks...

The only guide book which specifically deals with Cordon del Plata in Argentina. You can find it in Spanish and English versions. There's also a general section about altitude sickness, gear considerations etc. as well as a section about things to think about when attempting Aconcagua. As far as I know, the book is only available in Argentina and is easiest to find in Mendoza. This how the book cover looks like, so you know what to look for in the shops.