One source must be an e-book. Remember that one of the goals of the course is developing research skills and I would like you to know how to search for a book in the brick-and-mortar (i.e., the physical) library. Specifically, I expect you to search the library catalogue to find an e-book.
One source must be a journal article from a reputable publication in your field that is available in print. You can work from a digital copy available online as long as you’ve first tried to access the print version. [Update: Our library stopped subscribing to print journals in 2007.]
One source must be a magazine or newspaper article. For this one, you can use something online as long as there is a print version available somewhere. An example is The Arab News article on cloud seeding that ran in the print newspaper on September 24, 2017. You don’t need to look at the print version of this and probably wouldn’t be able to find it anyway. You can use the online version. The point is that sources in print are generally more reliable than sources on the Internet. If a print publication makes their articles available online, the articles are generally trustworthy.
The remaining three sources can be from the Internet and / or another book or e-book, another journal article in print or on ProQuest (or another scholarly database), or another magazine or newspaper article in print or on the Internet. In other words, the remaining three sources can be from any of the categories above and / or from a Google search. However, all the sources used in your report must be quality sources. (More on this later as we prepare for the midterm exam on evaluating sources.)
Please note that six sources is the minimum number. You are welcome to use more than six sources, however, and include them in your “References” at the end of your report.