This is a bibliography covering some of the philosophical and practical references to the concept and measurement of Complexity. It does not attempt to cover all the new sciences that might come under the "Complexity" banner, unless they are relevant to the idea of Complexity per se. Also, it does not include a very comprehensive amount on Computational Complexity due to restrictions on time and space.
A few of these are on-line, in which case I have provided the correct link. Most are not, which means you will probably have to go to a university or national library in order to actually read the texts referred to!
A purely text version (without the indexing, cross-referencing or comments) can be obtained here by ftp.
The comments reflect my opinion only. If anyone has any suggestions, or notices any mistakes or ommisions, then leave your comments here.