'Fundamentals of Philately' by L.M. and M Williams, published by the American Philatelic Society, 862 pages, the famous text, fine other than minor scuffing of dustjacket
'Australian Imperial Forces Postal History 1914-1918' by Bob Emery (1983), hardbound with 343 pages, still the most useful text on the subject, dustjacket faults and some spotting along tops of pages
Canada: 'Canadian Registered Letter Stamps & Cancellations 1875-1902' by E.A. Smythies & A.F. Smith (49pp), and Canada's Registry System: 1827-1911' by Horace W. Harrison, signed by author (1971, 84pp)
'The Pre-UPU Destination Mail of Victoria' by Ben Palmer (2009), hardbound and 313 pages. A detailed census of all overseas mail (except Great Britain) of Victoria up to 1891, essential for all postal history collectors. The limited edition seems to be well held and copies are offered only infrequently nowadays