00285nam a2200133Ia 4500020000900000082001000009100001900019245004400038250000600082260003900088300000800127500000900135650000700144  aNULL  a517.6  aFreeman, Harry 0aFinite Differences & Actuarial Students  a-  aLondonbCambridge University Press  a228  a2494  aNA