Keywords may be separated by AND and/or OR statements for greater control of the search results. For example, rocket AND cluster would generate a result set that contain both words. However, for cluster OR scale, the result set returned would contain both or either words.Exact matches can be searched for by enclosing keywords in double-quotes. For example, "cluster mount" would generate a result set which match the exact string. Brackets can be used for further control on the result set. For example, sheet and (balsa or basswood or "light plywood").