Use quoted strings to search for a sequence of words. For example "lake michigan" will find lake michigan but will not find a small lake in michigan.
Quoted strings prefixed with a minus sign are exclusion phrases. For example michigan -"lake michigan" will find all documents containing michigan but not containing the expression lake michigan (whether they contain the single word lake or not).
You can add excluded words at the beginning or at the end of a quoted string, to find documents that contain this quoted string not contiguously to these excluded words.
For example, "john -doe" will find documents that have at least one occurrence of john that is not part of the string john doe; but doe or even john doe can occur somewhere else in the document (for example, it will find john smith or john smith meets bob doe or even john smith meets john doe, but it will not find just john doe).
Another example: "-john -bob doe" will find documents that contain the word doe that is not part of the strings john doe nor bob doe (for example it will find greg doe or greg doe meets john smith but it will not find just john doe nor bob doe)