You are searching for information that is so specific that you have to be prepared for the possibility that none of it may be online. Or some may be, and some may not. In addition to searching on the Internet, you also need to make best friends with the reference librarian(s) in your local or college library.
At this webpage, you can go immediately to the search sites (first three columns across the top) -- or even better you can scroll down until you see the section called HOW TO SEARCH THE INTERNET. Those are the links to start with. You'll not only learn how to come up with good search terms, but also how to evaluate the webpages you get as results. Some will be good and others will be garbage. You need to know how to tell the difference.
My favorite way to search is to go to Google's advanced search page http://www.google.com/advanced_search?hl=en and put my search words or phrases into the first or second search box (either "all the words" or "exact phrase"). However, there many other strategies for searching you can use, and the HOW TO SEARCH THE INTERNET section will help you best. When I searched using some of your terms, here's what the results are:
Learning to use Google or other search engines can save you time and help you learn to find information efficiently. Here are some websites that can teach you how:
... and one to help you judge whether a particular website's information is worth your time:
The question itself:
It's asking you to separate "myths" from "factors" -- that is, fiction from facts.