- Change your search terms often and think of alternate ways to express your ides.
         "world war II"  --  "world war 1939 - 1945"  --  "second world war"

          military intelligence -- spy / spying / spies - espionage

- Look for seed documents on your topic (recent books, articles inside specialized encyclopedias), then mine the footnotes and/or bibliography for related sources.

- Pay close attention to book results - books are an important form of scholarly dissemination in the field of History. 

• Browse tables of contents to identify essay topics and to assess for relevance and scholarliness.
• Look for Subject Headings (they look like hashtags) in the item descriptions) to help improve your vocabulary.

- Use Google Scholar and LibrarySearch to check for who has cited the sources you've already found.

• For articles, check Google Scholar
• To discover books beyond the MRU collection, try WorldCat
• University of Calgary - Be sure to search within Books and Media to get to their book collection. Borrow items in person with a COPPUL card, available at MRU library circulation desk.
• Borrow items via interlibrary loan.

How to insert footnotes

MS Word​
Go to the references menu in the toolbar. Choose insert footnote. 
Word will insert a superscript number into your text and at the bottom of the page, where you can enter the publication details.

Word for Mac
Go to the insert menu in the toolbar. Choose footnote, and make sure numbering is set to continuous.

Google Docs
Go to insert in the toolbar, then select footnote from the drop-down menu.