21. A method performed by one or more computer devices, the method comprising: obtaining, by at least one of the one or more computer devices, a set of one or more addresses, each address, in the set of one or more addresses, corresponding to a respective first document, the set of one or more addresses being selected or identified by a user, receiving, by at least one of the one or more computer devices, a search query from the user after obtaining the set of one or more addresses; obtaining, by at least one of the one or more computer devices, a list of links to second documents based on the search query, where each address, in the set of one or more addresses, is obtained independently of the list of links and independently of the search query; filtering, by at least one of the one or more computer devices, the list of links, using the set of one or more addresses, to identify a subset of the links in the list of links, where the subset of the links includes fewer than all of the links in the list of links, filtering the list of links including: determining whether text associated with a body of a second document, corresponding to one of the links in the list of links, corresponds to a same topic as text associated with a body of the respective first document corresponding to an address in the set of one or more addresses, and including, in the subset of the links, the one of the links when the text associated with the body of the second document corresponds to the same topic as the text associated with the body of the respective first document; and providing, by at least one of the one or more computer devices, information regarding the subset of the links to the user.
21. A method performed by one or more computer devices, the method comprising: obtaining, by at least one of the one or more computer devices, a set of one or more addresses, each address, in the set of one or more addresses, corresponding to a respective first document, the set of one or more addresses being selected or identified by a user, receiving, by at least one of the one or more computer devices, a search query from the user after obtaining the set of one or more addresses; obtaining, by at least one of the one or more computer devices, a list of links to second documents based on the search query, where each address, in the set of one or more addresses, is obtained independently of the list of links and independently of the search query; filtering, by at least one of the one or more computer devices, the list of links, using the set of one or more addresses, to identify a subset of the links in the list of links, where the subset of the links includes fewer than all of the links in the list of links, filtering the list of links including: determining whether text associated with a body of a second document, corresponding to one of the links in the list of links, corresponds to a same topic as text associated with a body of the respective first document corresponding to an address in the set of one or more addresses, and including, in the subset of the links, the one of the links when the text associated with the body of the second document corresponds to the same topic as the text associated with the body of the respective first document; and providing, by at least one of the one or more computer devices, information regarding the subset of the links to the user. 23. The method of claim 21 , where obtaining the set of one or more addresses includes: including an address, associated with a document accessed by the user prior to the search query being received, in the set of one or more addresses.