TY  - BOOK
AU  - Ryder,Edward J.
TI  - Evaluation of lettuce varieties and breeding lines for resistance to common lettuce mosaic
T2  - United States. Dept. of Agriculture. Technical bulletin
AV  - S21 .A72 no. 1391
U1  - 633.5/2/7 
PY  - 1968///]
CY  - Washington]
PB  - U.S. Agricultural Research Service
KW  - Lettuce
KW  - Varieties
KW  - Lettuce mosaic disease
N1  - Bibliography: p. 2
ER  -