Surányi, S., and Z. Izsáki. “Effect of N, P and K Fertilisers and Their Interactions in a Long-Term Experiment on Winter Barley (Hordeum Vulgare L.)”. Acta Agraria Debreceniensis, no. 70, Oct. 2016, pp. 87-92, doi:10.34101/actaagrar/70/1823.