Meyer-Berthaud, B.; Galtier, J. (1986). Studies on a lower carboniferous flora from Kingswood near Pettycur, Scotland. II. Phacelotheca, a new synangiate fructification of pteridospermous affinities. Review of Palaeobotany and Palynology. 48(1-3): 181-198.
Studies on a lower carboniferous flora from Kingswood near Pettycur, Scotland. II. Phacelotheca, a new synangiate fructification of pteridospermous affinities