N. K. B.  Robson, ?British and Irish St John's worts: 2.?, Wild Flower Mag., vol. no.399, pp. 18-22 (1984) - illus., chrom. nos., 1984.

N. K. B.  Robson, ?British and Irish St. John's worts: 3.?, Wild Flower Mag., vol. no.400, pp. 13-16 (1984) - illus., chrom. nos., 1984.

N. K. B.  Robson, ?British and Irish St. John's worts: 1. Introduction and shrubby species.?, Wild Flower Mag., vol. no. 398, pp. 22-25 (1983)- illus., 1983.

N. K. B.  Robson, ?British and Irish St. John's Worts: 4. Hypericum linariifolium and H. humifusum.?, Wild Flower Mag., vol. no.401, pp. 22-25 (1984) - illus., 1984.