Keywords may be separated by AND and/or OR statements for greater control of the search results.
For example, transmitter AND receiver would generate a result set that contain both words. However, for transmitter OR amplifier, the result set returned would contain both or either words.
Exact matches can be searched for by enclosing keywords in double-quotes.
For example, "audio amplifier" would generate a result set which match the exact string.
Brackets can be used for further control on the result set.
For example, Transmitter and (receiver or antenna or "power amplifier")