1. Agsteribbe, E. & Groenhuijzen, S. (1948). De Ankeveense Plassen en hun Mosflora. Buxbaumia, 2, pts. 3–4, 34–8. Summary in English. Deals with bryophyte ecology of a complex area of peat bogs and waterways. In Sphagnum bogs of pH 5.4 S. squarrosum and S. fintbriattun were the chief species encountered.
2. Allorge, P. (1947). Essai de Bryogiographie de la Pértinsule Ibérique. Documents reunis par Madame Pierre Allorge, 114 pp. 15 figs. 2 maps and 8 pls. Paris 1947.