⁶Lhwyd, Edward. "Several Observations Relating to the Antiquities and Natural History of Ireland, Made by Mr. Edw. Lhwyd, in His Travels Thro' That Kingdom. In a Letter to Dr. Tancred Robinson, Fellow of the College of Physicians and Royal Society." Philosophical Transactions (1683-1775) 27 (1710-1712): 503-06.