Further reading Sefi, A.J. An Introduction to Advanced Philately, with special reference to typical methods of stamp production. London: Rowley & Rowley, 1926 (2nd edition 1932) (Electronic facsimile edition Royal Philatelic Society London 2010). Sutton, R.J. & K.W. Anthony. The Stamp Collector's Encyclopaedia. 6th edition. London: Stanley Paul, 1966. Williams, L.N. & M. Fundamentals of Philately. State College: The American Philatelic Society, 1971.
furTHer rEading seFi, a.j. An introduCtIon To AdVaNceD pHILaTelY, with SpECIal RefErence to TYPiCal mEthoDs Of sTaMP producTiOn. LONdon: roWley & rowlEy, 1926 (2nd eDItiON 1932) (elECtronIc FacSiMilE editiON royal PhIlAtElIc society LondON 2010). SuTtoN, R.J. & k.w. anthoNy. thE stamp cOlleCtor's eNcyclopAeDia. 6th eDiTioN. LonDON: sTANlEy PauL, 1966. wilLiams, l.n. & M. FundamenTals of PHilatELy. StaTE COllege: the ameRicAn philateLic socIety, 1971.