00284nam a2200109Ia 4500008004100000082002400041100002200065245005100087260000900138300001000147650001700157140113s9999    xx            000 0 und d  a632.953.2:633.49 L2  a" de Bokx, J. A."  aViruses of potatoes and seed-potato production  b1972  a233p.  aPotato virus