Blind Signature :
http://www.princeton.edu/~usgvote/technical/paper/
http://ganges.cs.tcd.ie/mepeirce/Project/Chaum/sciam.html
http://www.ce.uni-linz.ac.at/uebung/prost/Sem%20ABWL%20-%20ECash/DigiCash/www.digicash.com/news/archive/encrypt.html
http://www-swiss.ai.mit.edu/6.805/articles/money/cryptnum.htm
http://www.iks-jena.de/mitarb/lutz/security/cryptfaq/q39.html
http://www-path.eecs.berkeley.edu/~msoper/documents/digital_cash/node23.html
http://yaksi.eco.saitama-u.ac.jp/~kawagoe/auc.html
http://www.replay.com/mirror/privacy/p2.4.1.2.html
http://www.ubs.ch/e/index/about/ubilab/ext/publications/e_sta95.htm

Cryptography:
http://www.iacr.org/~iacr/

Digital Cash:
http://www.stack.nl/~galactus/remailers/
http://www.privacy.org/
http://privacy.net/

E-Commerce:
http://www.nafta.net/ecedi.htm
http://ecommerce.internet.com/
http://www.w3.org/ECommerce/

Privacy:
http://www.stack.nl/~galactus/remailers/
http://www.privacy.org/
http://privacy.net/

Micro Payment:
http://collagen.aloe.co.kr/~hongjig/docs4/WD-mptp-951122.htm
http://www.people.cornell.edu/pages/jk25/Project/Introduction%20To%20Micro.htm
http://www.ce.uni-linz.ac.at/uebung/prost/Sem%20ABWL%20-%20ECash/DigiCash/www.digicash.com/news/room/art/gartners01.html
http://www.krnet.or.kr/krnet99/A/A1_1/sld018.htm