 SIGLE (System for Information on Grey Literature in Europe) was a unique multidisciplinary bibliographic database dedicated to grey literature.Up to 15 European partners participated in SIGLE, mostly national libraries or important research libraries.Created in 1980 and produced from 1984 onwards by EAGLE (European Association for Grey Literature Exploitation), the database was last available through STN International and on CD-ROM via Silverplatter/Ovid Technologies, until it stopped input in 2005.