Desing and research; Oosterban. R.J.;Drainage systems; Knops. J.A.C.;Installation methods; Boels. D.;Steady state drainage in heterogeneous and anisotropic media; Wolsack. J.;Second and third degree equations for the determination of the spacings between parallel drainage channels; Ernst. L.F.;Drainage calculations in stratified soils using the anisotropic soil model to simulate hydraulic conductivity conditions; Boumans. J.H.;The hydraulic conductivity in heterogeneous and anisotropic media and its estimation in situ; Guyon. G.;Pre-drainage research in land consolidation areas; Meer. W. van der;Notes on the approach to drainage design; Zaslavsky. D.;Choice of a field drainage treatment; Devillers. J.L.;Soils functions and drainage; Ericksson. J.;An electric analog unsaturated flow and accumulation of moisture in soils; Wind. G.P.;Drainage of clay soils in England and Wales; Bailey. A.D.;Reclamation of peats and impermeable soils; Galvin. L.F.;Regulation of water regime of heavy soils by drainage, subsoiling and liming and water movement in this soil; Schuch. M.;Drain envelope materials in Canada; Irwin. R.W.;Synthetic drain envelope materials; Willardson. L.S.;The influence of envelope materials in preventing silting-up of drain pipes; Dierickx. W.;Testing synthetic fabrics for use with drainage conduits; Ochs. W.J.;The entrance resistance of drains as a factor in design; Wesseling. J.;Research on envelope materials for subsurface drains; Knops. J.A.;Model tests on drainage materials; Zuidema. F.C.;Composing a drainage pipe line out of sections with different diameters; Cavelaars. J.C.