Update (Saturday, December 20, 2014):
We are pleased to report that the issue with our search engine has been resolved, particularly with respect to cardinality and associated features. We are monitoring the system closely. If you experience any other issues with Scopus, please contact the help desk using "Help and Contact" link in Scopus.
Original Post (Friday, December 19, 2014):
Scopus is experiencing an issue with its search engine, particularly with respect to cardinality.