1. Microspores in coals of the Limestone Group in Scotland;Knox;Trans. Instn. Min. Engrs., Lond.,1948
2. Microscopic coal research in Canada;Hacquebard;Leid. Geol. Meded.,1955
3. The spores of Lycopodium, Phylloglossum, Selaginella and Isœtes and their value in the study of microfossils of Palæozoic age;Knox;Trans. Bot. Soc. Edin.,1950
4. The spore genera from the Upper Carboniferous coals of the Saar and their value in stratigraphic studies;Bhardwaj;Palœbotanist,1955