I have published these documents on the Web in the hope that others will use them for teaching and learning. The copyright notices are there to provide recourse in the event of abuse, not to keep you from using this material. Most of this material is licensed under the Creative Commons Attribution License with restriction to non-commercial use and restriction on creation of derivative works. Material licensed another way will have specific license terms incorporated in the document.
Educators may reproduce an unlimited number of copies of any of my documents published here for distribution without charge to students. You must reproduce the material unchanged, including retaining the copyright notice. (If you find errors, please write to me at: and I'll correct them.)
Educators, bookstores, copy shops, academic departments and the like may reproduce an unlimited number of copies of any of my documents published here for sale to students at a price that does not significantly exceed the cost of duplication, stocking and sale. You must reproduce the material unchanged, including retaining the copyright notice.
If you want to reprint any of this material for profit, I'm for it because I want some of the profit, too! Let's talk.
If you want to use this material on a Web page, please do so with a link rather than by copying the material; this lets me correct errors and otherwise update my work. Electronic copying or the creation of derivative works requires specific permission beyond that granted here.
In a few cases, generous people have allowed me to republish their material on my Web page. If you want to use such material, please contact the author of the material directly. This permission to copy covers only my own work.
If you are reproducing this material for free distribution to students, or for sale at a price that recovers cost, your copying and printing service may require a copyright release letter. I have prepared a generic letter that is probably sufficient for most cases. If that isn't good enough and you need a specific letter, please send me e-mail. () I can probably provide the letter you need. (If you know what it must say, please include the required text in your message.)
If you are wondering why I bother with copyright notices at all, please read Why Copyright Web Documents? by Peter Suber.
Originally posted: 2000-08-27
Creative Commons license added: 2006-08-06
Revisions since 2000-08-27 have changed the form of this document,
but have not altered the intended meaning.