Since 1965, Ulrich von Schroeder has been studying Buddhist art and culture as an independent scholar. The results of his numerous field trips are published in several monumental volumes. Indo-Tibetan Bronzes, published in 1981, is generally considered the best monograph on the stylistic development of metal sculptures in the Indo-Tibetan cultural region. In 1990 Buddhist Sculptures of Sri Lanka was published. This volume, with 1610 illustrations, is the result of seven years of field research in Sri Lanka and Southeast Asia. In 2001 Ulrich von Schroeder published Buddhist Sculptures in Tibet, illustrating in two volumes more than 1100 previously unpublished sculptures discovered in Tibet during fourteen expeditions over a period of nine years. The first volume documents sculptures from India and Nepal in Tibetan monasteries. The second volume illustrates Buddhist sculptures made in Tibet and China. Another publication is 108 Buddhist Statues in Tibet: Evolution of Tibetan Sculptures, published in 2008.