A.  Leip, Weiss, F., Lesschen, J. Peter, and Westhoek, H., ?{The nitrogen footprint of food products in the European Union}?, The Journal of Agricultural Science, vol. 152, pp. 20?33, 2014.

A.  Leip, Leach, A. M., Musinguzi, P., Tumwesigye, T., Olupot, G., Tenywa, J. Stephen, Mudiope, J., Hutton, O., Cordovil, C. Md.S., Bekunda, M., and Galloway, J. N., ?{Nitrogen-neutrality: a step towards sustainability}?, Environmental Research Letters, vol. 9, p. 115001, 2014.

D.  Vanham, Leip, A., Galli, A., Kastner, T., Bruckner, M., Uwizeye, A., van Dijk, K., Ercin, E., Dalin, C., Brandão, M., Bastianoni, S., Fang, K., Leach, A. M., Chapagain, A., Van der Velde, M., Sala, S., Pant, R., Mancini, L., Monforti-Ferrario, F., Carmona-Garcia, G., Marques, A., Weiss, F., and Hoekstra, A. Y., ?{Environmental footprint family to address local to planetary sustainability and deliver on the SDGs}?, Science of The Total Environment, vol. 693, p. 133642, 2019.