  Number of published scholarly articles is growing exponentially. To tackle
this information overload, researchers are increasingly depending on niche
academic search engines. Recent works have shown that two major general web
search engines: Google and Bing, have high level of agreement in their top
search results. In contrast, we show that various academic search engines have
low degree of agreement among themselves. We performed experiments using 2500
queries over four academic search engines. We observe that overlap in search
result sets of any pair of academic search engines is significantly low and in
most of the cases the search result sets are mutually exclusive. We also
discuss implications of this low overlap.
