The British Carboniferous Producti : II. Productus (sensu stricto); Semireticulatus and Longispinus groups /
by Helen Marguerite Muir-Wood.
- London : H.M. Stationery Off., 1928.
- 217, [1] p, 12 l. incl. ill. : XII pl. ; 28 cm.
- Gt. Brit. Geological survey. Memoirs ... palæontology ; v.3, pt.1 .