Supported types of searches:

• Single keyword search
  The search engine returns pages containing the keyword.
  Ex: tutorial
• Multiple keyword search
  By default, the search engine only returns pages containing all of the keywords. This is the same as using the AND operation between each word.
  Ex: injection volume
• Phrase search
  Put a search phrase in quotes to only return pages containing the exact phrase.
  Ex: "void fraction"
• Boolean search
  The AND operator indicates that the keyword before and after must be present on the page.
  The OR operator indicates that either the keyword before and/or the keyword after must be present on the page.
  A '+' sign before a keyword indicates that it must appear on the page.
  A '-' sign before a keyword indicates that any page containing the keyword should not be returned.
  Ex: flow AND rate
  Ex: "Van Deemter" OR "resolution"
  Ex: chromatography -gas