1) Chihuahuas are the Best! (2010) by Elaine Landau.

2) Chihuahuas for Dummies (2007 2nd edition) by Jacqueline O'Neil.

3) Chihuahua: Senor Tiny (Little Dogs Rock!) (2009) by Natalie Lunis.

4) Little Dogs: Training Your Pint-Sized Companion (2007) by Deborah Wood.