Abbreviation Link
SW The Uniform Coinage of India 1835 to 1947: a Catalogue and Pricelist by Stevens, P. and Weir, R.
PR THE COINS OF THE BRITISH COMMONWEALTH OF NATIONS, Part – 4 India. Volume 2 : Uniform Coinage East India company 1835-58 and Imperial Period 1858 – 1947. Author – F. Pridmore
KM  Krause & Michler
GK Standard Catalogue of Coins of British India 1835 to 1947 Currency Issues Authors – Gev Kias and Dilip Rajgor
HA   Heritage Auctions
BAL   AH Baldwin & Sons ltd