To avoid typing long strings separated
by OR (e.g. child OR child's OR children OR children's OR childhood),
use a symbol. Replacing all letters after the first "d"
(child*) allows you to search variations of this
word. This is called truncation.
When the variation is
within a word (e.g. woman OR women), use
a wild card to replace the variant letter (e.g. wom*n).
WARNING:Take care not to truncate
a word too abruptly. Typing opera* to search
for forms of operations will also retrieve
opera, operant and other variations.