Complex sentence: Some of the older headstones were readable in the 19th century and half a dozen appear in John Martine's book "Fourteen Parishes of the County of Haddington", by John Martine, Edinburgh, 1890.
Split into simpler sentences: Some of the older headstones were readable in the 19th century and half a dozen appear in John Martine's book. Refer: "Fourteen Parishes of the County of Haddington", by John Martine, Edinburgh, 1890.