Carrier Recovery

I am looking for references on Carrier Recovery (Costas Loops, Squaring Loops, etc).

Any ideas ?

May help:
http://www.hyperception.com/pdf/appn...s/hsap2031.pdf
http://www.wj.com/pdf/technotes/PSK_demod_part1.pdf
http://eceweb.uccs.edu/wickert/ece56...es/N5675_1.pdf