California citrus pests and their control; a description of various citrus pests of economic importance in California, with general control recommendations,

Mode of access: Internet.

Insects of economic importance; outlines of lectures in economic entomology,

Bibliography: p. 9

Determination of maximum permissible levels of selected chemicals that exert toxic effects on plants of economic importance in Illinois,

Bibliographical references.

Insects of economic importance; outlines of lectures in economic entomology,

"Entomological literature": p. 6-7.

Stem sawflies of economic importance in grain crops in the United States,

"Literature cited": p. 37-50.

The southern potato wireworm : its biology and economic importance in coastal South Carolina /

Cover title.

The economic importance of timber in the United States /

"July 1963."

The strength of the people; a study in social economics,

Introductory.--The economic aim.--The statesman's question.--The source of poverty.--The remedy.--Progress during the nineteenth century.--The economic importance of the family.--The children.--The aged.--Work and wages.--Conclusion.--Index.

The importance of bird life: a popular account of its economic significance and conservation,

Mode of access: Internet.