Clan Ledger Watermark from the Grand Imam Yousouf collection (N'Guigmi, Niger, 2010)   Publication Date:   [n.d.] Publisher:   Clan Ledger Type:   Photograph Source Institution:   SOAS, University of London Subject Keyword:   Watermarks دمغ بعلامة مائية Filigranes Wasserzeichen Clan Ledger (paper manufacturer) Spatial Coverage:   Europe Genre:   Watermarks Clan Ledger Watermark from the Grand Imam Yousouf collection (N'Guigmi, Niger, 2010)