Michele 
This booklet, "Cartophilic Reference Book - No.20 : The Australasian Miscellaneous Booklet - The Cigarette Card Issues of Sniders & Abrahams Pty., Ltd., and Other Miscellaneous Tobacco Issues in Australia and New Zealand - Published by the Cartophilic Society of Great Britain Limited" (or RB.20), was edited by Edward Wharton-Tigar, and signed off in November 1951.
It was then printed, by Collins & Wilson (T.U.) London E.C.1., as a booklet of fifty-six pages, but with thirty-five illustrations showing one hundred and thirty-six cards - and published as a limited edition of five hundred copies, in 1951, to be retailed, to Society members, at ?
Like all our individual reference booklets, it was superseded by The World Tobacco Issues Index (RB.21), which was issued in 1956.
However we know that after that time these books still remained in stock as when the Cameric Club merged with the Cartophilic Society, this was amongst the books listed as part of a half price offer, so that former Camericans, and new members, could buy one. By that time the normal retail price had risen to thirteen shillings and sixpence, but the offer reduced it to six shillings and nine pence.