<AND>
Selects documents that contain all of the search elements you specify. (To search for the word AND, enclose AND in double quotes.)
computer <AND> laptop, Lewis "and" Clark
<ACCRUE>
Selects documents that include at least one of the search elements you specify. The more search elements that are present, the higher the score will be.
<ACCRUE> (computer, laptop)
<OR>
Selects documents that show evidence of at least one of the search elements you specify.(To search for the word OR, enclose OR in double quotes.)
nation <OR> region, left "or" right
