Williamson, W. C. (1887). A monograph on the morphology and histology of Stigmaria ficoides. Printed for the Palæontographical society.
Lua i Stíl Chicago (17ú heag.)Williamson, William Crawford. A Monograph on the Morphology and Histology of Stigmaria Ficoides. London: Printed for the Palæontographical society, 1887.
Lua MLA (8ú heag.)Williamson, William Crawford. A Monograph on the Morphology and Histology of Stigmaria Ficoides. Printed for the Palæontographical society, 1887.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.