Cyfrol o lyfrgell y Parchedig John Herbert Roberts, Y Drenewydd, diweddar ŵr Mrs Roberts, yn cynnwys traethawd ar 'Hanes dechreuad a chynydd Ymneillduaeth ym mhlwyf Llanasa', sir y Fflint, gan 'Ymneillduwr'; ynghyd â nodiadau diwinyddol, 1922, yn llaw'r Parchedig John Herbert Roberts / A volume from the library of the late Reverend John Herbert Roberts, Newtown, husband of Mrs Roberts, containing an essay in Welsh on the beginning and growth of Nonconformity in the parish of Llanasa, Flintshire, by 'Ymneillduwr'; together with theological notes, 1922, in the hand of the Rev. John Herbert Roberts

Extracts and transcripts from the parish registers of Llanasa, 1619-1871, with an annotated list of vicars; extracts from the vestry book, 1859-1912; transcripts of tombstone inscriptions; and notes on church plate.