3.23. How am I going to remember this?
Fortunately there are on-line compilations of most of the information presented in this section. In particular the AstroWeb consortium is probably one of the best places to start surfing. There are several versions of AstroWeb at:
All of them validate the links daily and report on those that are not accessible.
Finally the web crawlers and cyber-robots that mine the information superhighway are very helpful to find obscure links, some are: