Authors: Boelaars, Henri --- Bouman, Cornelis Adrianus --- De Gier, Gérard --- Van Leeuwen, Bertulf --- Ramselaar, A. C. --- et al. Schoonenberg, Piet J. A. M. --- Thijssen, F. --- Vermeulen, J. H. A. --- Weterman, J. A. M.
Year: 1954 Publisher: Utrecht : Spectrum,