In various embodiments, multiple heterogeneous documents are processed to identify structures, such as chemical structures, contained therein, including non-embedded structures. Also described is a graphical user interface that permits a user to search for a structure or substructure within a set of electronic documents, then displays the matching structures as well as the actual pages of the documents on which the matching structures are found. Display of the actual pages allows the user to verify the matches and provides helpful context for the user.