1. Adam, Y. and Runfola Y., 1971. Numerical Resolution of diffusion equation, Rapport N. 9, Progr. Nat. Environnement Physique et Biologique, Projet Mer.
2. Adam, Y., 1975. A Hermitian finite difference method for the solution of parabolic equations, to be published.
3. Nitrification in the Scheldt Estuary (Belgium and the Netherlands);Billen;Estuarine and Coastal Marine Science,1975
4. Billen G. and Smitz J., 1975. A mathematical model of oxido-reduction processes in the Scheldt Estuary, Math Modelsea - ICES Hydrography Committee C. M. 1975, C:21.
5. Billen, G., Smitz, J., Somville, M. and Wollast, R., 1976. Degradation de la matière organique et processus d'oxido-reduction dans l'Estuaire de l'Escaut. Prog. Nat. R-D Environnement - Projet Mer - Rapport Final - vol X, p. 102 - 152.