1. On-line information about the existing linear collider projects can be found on the following URLs; CLIC: http://www.cern.ch/CERN/Divisions/PS/CLIC/Welcome.htmll;
2. JLC: http://jlcux1.kek.jp/index-e.html;
3. NLC: http://nlc.physics.upenn.edu/nlc/nlc.http;
4. TESLA: http://www-tesla.desy.de:8030/.
5. A comprehensive bibliography of high energy e− e− scattering can be found in hhttp://www.hep.psi.ch/e-e-.html