00333nam a2200109Ia 4500008004100000100002000041245005900061260006400120300001000184650001100194650001800205220216s9999    xx            000 0 und d  aDissanayake A B 0aEconomic life span of the rubber tree in smallholdings  bRubber Research Institute of Ceylon Quarterly Journalc1968  a49-53  aRubber  aSmallholdings