Guide to the chemicals used in crop protection.
Subtitle: 4th ed. Supplement [by] E.Y. Spencer.
Contributors: Spencer, Elvins Yuill, 1914-
Edition: 4Th ed.
Series: Canada.  Dept. of Agriculture.  Publication, 1093
Publisher: Queen's Printer]
Published: 1964
Place of publication: [Ottawa
Language: eng
Subjects: Pesticides