Extension documentation

Hello, One quick question I forgot to ask the other day when discussing the new extension I am trying to write. I have been looking for documentation either on PHP or the Zend engine as far as a tutorial or reference material on how to create PHP extensions. Of main interest is list of the functions/defines/macros used in writing extensions. I have found a couple of very useful sites, but nothing definitive that gives detailed API instructions or descriptions. To get my extension this far, I used the tutorial on Zend's website (http://www.zend.com/php/internals/extension-writing1.php), but it doesn't give me all the information I need. I know of the documentation in the standard PHP documentation describing the PHP and Zend API's, but it is not as complete as I would like. Maybe this is all PHP offers, but if anyone knows of anything more in depth, that would be helpful. Any nudges in the right direction would be much appreciated.