child* retrieves documents with child, children, childbirth, childbearing, childish, and so forth.
Adjacent words automatically treated as a phrase; no special punctuation required.
north pole retrieves only documents in which the words north and pole appear next to each other, in that exact order.
lincoln AND douglas retrieves only documents that contain both lincoln and douglas.
lincoln OR douglas retrieves documents that contain either lincoln or douglas.
Wn terms must appear within n words in the specified order.
Nn terms must appear within n words of one another, in any order.
henry W2 thoreau retrieves documents with henry david thoreau or henry thoreau.
henry N2 thoreau retrieves documents with henry thoreau, henry david thoreau, or thoreau, henry david.