Columbia subject headings:
Environmental policy--North America--International cooperation--Handbooks, manuals, etc.
Environmental protection--North America--International cooperation--Handbooks, manuals, etc.
Labor contract--North America--Handbooks, manuals, etc.
Labor--North America--International cooperation--Handbooks, manuals, etc.
Harvard subject headings:
Environmental policy--International cooperation--North America.
Environmental protection--International cooperation--North America.
Labor contract--North America.
Labor--International cooperation--North America.
Princeton subject headings:
Environmental policy--North America--International cooperation--Handbooks, manuals, etc.
Environmental protection--North America--International cooperation--Handbooks, manuals, etc.
Labor contract--North America--Handbooks, manuals, etc.
Labor--North America--International cooperation--Handbooks, manuals, etc.