Papurau y Parch. Evan Wyn Williams, 1966-1969, yn cynnwys papurau'n ymwneud â thrychineb Aberfan, 1966-1968; a phapurau'n ymwneud â chanmlwyddiant Capel Coffa (1869-1969) Edward Jones ym Mathafarn = Papers of Rev. Evan Wyn Williams, 1966-1969, comprising papers relating to the Aberfan disaster, 1966-1968; and papers relating to the centenary of Capel Coffa (1869-1969) commemorating Edward Jones at Bathafarn.