1. A method for querying a knowledge resource comprising: providing a querying system which is configured for executing queries in a query language that accepts global backreferences that are not limited to being located in a respective condition which includes a regular expression to which the global backreference refers; receiving an input query which seeks information from the knowledge resource; with the querying system, based on the input query, executing a query containing a global backreference comprising retrieving results from the knowledge resource responsive to the query, the query including a set of conditions, a first of the conditions including a regular expression that identifies strings in the knowledge resource that match the regular expression, the regular expression including a capturing group for capturing a substring of an identified matching string, the global backreference retrieving the substring captured by the capturing group and wherein the global backreference comprises a remote backreference which is outside the first condition; and outputting at least one of the results of the query containing the global backreference and information based on the results.