British Solomon Islands
W Barber, The Impressed Duty Stamps of the British Colonial Empire (update to 1st Edition, privately published, Chesapeake, Virginia, 2009)
J Barefoot Ltd, British Commonwealth Revenues (9th Edition, privately published, 2012)
A Forbin, Catalogue De Timbres Fiscaux Dans Le Monde Entier (3rd Edition, privately published, 1915)
Stanley Gibbons, Commonwealth & British Empire Stamps 1840-1952 (107th Edition, Stanley Gibbons Ltd, Ringwood, 2004)
W Morley, Catalogue of the Revenue Stamps of the British Colonies including Railway Stamps (2nd edition, privately published, 1910)
I owe a huge debt of gratitude to David Beech and Paul Skinner at the British Library for their help and expertise, and for allowing me access to the Library's extensive Philatelic Collections including the Crown Agents Requisition books and proof material.
When reproducing images of stamps not in my own collection, I have sought the permission of the current owner whenever possible, though in some cases the current owner is not known to me. If I have inadvertently broken any rules of copyright, please help me to comply by bringing this to my attention.