TY  - RPRT
TI  - Letter Circular 651: variety reduction effected by the application of simplified practice (supersedes Letter Circular 504)
PY  - 1941
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 651
DO  - 10.6028/NBS.LCIRC.651
ER  -