Here are some great article about separation Anxiety.

http://www.dog-obedience-training-review.com/separation-anxiety-in-dogs.html

http://www.doganxietycures.net/

http://www.humanesociety.org/animals/dogs/tips/separation_anxiety.html

http://www.metpet.com/Reference/Dogs/Training/separation_anxiety_in_dogs.htm

http://www.dogbreedinfo.com/separationanxiety.htm

http://www.petlibrary.co.uk/1/separation-anxiety-in-dogs-how-to-treat-it/