Columbia subject headings:
Harvard subject headings:
Air conditioning--Equipment and supplies--Periodicals.
Heating--Equipment and supplies--Periodicals.
Refrigeration and refrigerating machinery--Periodicals
Princeton subject headings:
Air conditioning--Handbooks, manuals, etc.
Heating--Handbooks, manuals, etc.
Refrigeration and refrigerating machinery--Handbooks, manuals, etc.
Ventilation--Handbooks, manuals, etc.