TY  - BOOK
AU  - Weir , Wilbert Walter 
TI  - Productive soils: the fundamentals of successful soil management and profitable crop production
U1  - 631.4 21st ed.
PY  - 1920///
CY  - Philadelphia
PB  - J. B. Lippincott
KW  - Soil fertility
KW  - Soils-Classification
KW  - Soils-Composition
N1  - Index: pp 385-98
ER  -