Q:The book An Essay on the Principle of Population was first published in 1798 under the alias Joseph Johnson. but the author was soon identified as Thomas Robert Malthus. While it was not the first book on population it has been acknowledged as the most influential work of its era. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Written Work