Hello, everyone, I have a question about reference in word.

I use word 2007. I used it for my thesis.
I have seven chapters in seven word files. Each chapter has its own reference (endnote) at the end of the chapter.
Now I am trying to combine 7 chapters into one word file but all the references will combine at the very end of the document. How can I do to let each chapter has its own reference section and number in one word file?

please help me. thank you.