00270nam a2200109Ia 450000500170000000800410001708200120005810000190007024500270008926000360011630000080015220260224040801.0260224s9999||||xx |||||||||||||| ||und||  a630 NOR  aNorman, A.G.   0aAdvances in agronomy.   aNew York: Academic Press.c1952  a414