Cross references link up text sections (Networks) in reference works and documents. The encyclopaedia, which became successful in the Enlightenment and a commercially fl ourishing publishing product (Publisher) in the 19th century, achieved not only the linear presentation of knowledge (Science) in its entirety, but also interlinked it in an intricate network by using cross references. The Internet and the World Wide Web in particular have made the technical option of clickable hyperlinks into a major feature in the digital presentation of information of all kinds.

The first encyclopaedia to use cross references systematically to network entries in it is seen to be the dual volume Cyclopædia, or, An universal dictionary of arts and sciences von Ephraim Chambers from the year 1728 (London). In addition to the significant role he played in the history of the encyclopaedia, Chambers’ can also be regarded as the inventor of the predecessor to the hypertext. Digital editions of large encyclopaedias nowadays contain millions of cross references.