My friend is studying for an MA in Teaching Chinese as a Foreign Language at a HK-based uni and is looking for used books or cheap books. Can anyone make recommendations where to buy either online from a local site or from a store or 1:1

Photocopying is not an option.

Seeking the following books:

1. Xing, Janet Zhiqun. 2006. Teaching & Learning Chinese as a Foreign Language.
2. Ellis, R. 1985. Understanding Second Language Acqusition. OUP
3. Saville-Troike, M. 2006. Introducing Second Langauge Acquistion. Cambridge: Cambridge University Press.

Any suggestions appreciated.