1. A method performed by a computer system, comprising: storing a version of a paper, the version being displayable on a display device as a likeness of the paper; at a first location within the version, detecting a reference to a second location, wherein the second location is external to the paper, and wherein the detected reference is at least one of the following, other than a computer network address: an alphanumeric character, a symbol; a term; and a phrase; in response to the detected reference, embedding a hyperlink within the detected reference at the first location, wherein the second location is a file external to the paper, wherein the file includes audio signal information, and wherein the hyperlink is selectable at the first location by a user to cause an operation associated with the second location; and while the first location is displayed on the display device, highlighting the first location to indicate the hyperlink as being selectable at the first location by the user to cause the operation associated with the second location, wherein the operation includes outputting audio signals in response to the audio signal information and a selection of the first location by the user.