Literaturrecherche

Literatur Helal M (1994) Uptake of heavy metals by crop plants. In: Egyptian-German seminar on environmental research : Cairo, 21 - 23 March 1994. Cairo, p 10

Literatur Helal M, Issa GI (1994) Low input concept for desert agriculture. In: Egyptian-German seminar on environmental research : Cairo, 21 - 23 March 1994. Cairo, p 16