How do I find the paper of electronic version？?

Very hard. There is no information on the scanned pages to indicate where it came from. Do you have any idea who wrote it or published it? Or what the title of the full item is? It looks like a chapter from a book, rather than an article or report. I am also concerned that it says PREVIEW in a watermark across it, which suggests that this is a pre-publication copy so the full version might never have been published.

I am assuming that you want to use this in an essay or similar. I suggest that you take the information that you require from it and look for another book or report that also contains that information. You can then quote that.

Agree with Stinley, this looks like a pretty dicey source. If you are using this for a research paper, try using Google Scholar or a database that your school has access to such as JStor.