Symptoms of virus diseases in plants. by L. Bos Bos, L. 1928- Virus diseases of plants. SB736 .B63 1971 581.2 BOS "With indexes of names of symptoms in English, Dutch, German, French, Italian, and Spanish." Bibliography: p. 141-163. Wageningen. [Pudoc, 1971] 1971] 1971 Text 225 p. : eng