The vast scope of The Encyclopedia of Exploration makes it a work unlike any other in its combination of historical, biographical and bibliographical data. It includes a catalogue of all known expeditions, voyages and travels from the earliest times to the year 1940, as well as biographical information of the travellers themselves, which places them in their historical context. The Encyclopedia of Exploration has been a massive undertaking. The five volumes include over 5100 articles in approximately 4200 pages, some 4 million words. Within the text itself there are many thousands of cross-references between articles, and the work is made even more accessible through extensive bibliographical citations to accompany the articles.