phpandwebservicewithwsdl

Following are the links:

1. Developing Web Services Using PHP
2. PHP Web Services with WSDL
3. Creating Web Services with PHP and SOAP, Part 1
4. Creating Web Services with PHP and SOAP, Part 2
5. wsdl2php Manual
6. Web Services – WSDL: Creating SOAP Server
7. WSDL Document Example

Edit:

The SoapClient class is used in latest version of php(5.3 & up).