Integrating web sites to provide more efficient services is a very promising way in the Internet. For example searching house for rent based on train system or preparing a holiday with several constrains such as hotel, air ticket, etc... From resource view point, current web sites in the Internet already provide quite enough information. However, the challenge is these web sites just provide information but do not support any mechanism to exchange them. As a consequence, it is very often that a human user has to take the role to “link” several web sites by browsing each one and get the concrete information. The reason comes from a historical objective. Web sites were developed for human users browsing and so, they do not support any machine-understandable mechanism. Current researches in WWW environment already propose several solutions to make newly web sites become understandable to other web sites so that they can be integrated. However, the question is how to integrate existin...