The Dehkhoda Dictionary (Persian: لغت‌نامهٔ دهخدا‎‎) is the largest comprehensive Persian dictionary ever published, comprising 16 volumes (more than 27000 pages). The complete work is an ongoing effort that entails over forty-five years of efforts by Ali-Akbar Dehkhoda and a cadre of other experts. Although Dehkhoda covers a big part of literary terms and words in Persian language, it also lacks most of scientific and technology terms coined and loaned during the past decades. Dehkhoda states in the preface of the dictionary that "Not only this book misses 2/3 of today’s entire Persian vocabulary, at least half of the words I knew were forgotten and not recorded in this book." Many of those words were added after his death.