Ōjōyōshū

A classic text of Japanese Pure Land Buddhism composed in the year 985 by the Tendai monk Genshin (942-1017). This work lays out 25 different methods of visualizing the Buddha Amitābha, and was primarily aimed at meditation masters within the ranks of Tendai clergy rather than at the population at large. In this work, Genshin took 617 extracts from 112 scriptures and treatises having to do with Pure Land practice and arranged them topically, fashioning a comprehensive compendium of Pure Land thought. This systematic arrangement of Pure Land literature proved very influential not only in Japan, but also in China where it became a widely used reference work.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)