Langley, B. C. (1990). Heating, ventilating, air conditioning, and refrigeration (4th ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Langley, Billy C. Heating, Ventilating, Air Conditioning, and Refrigeration. 4th ed. Englewood Cliffs, N.J: Prentice-Hall, 1990.
Lua MLA (9ú heag.)Langley, Billy C. Heating, Ventilating, Air Conditioning, and Refrigeration. 4th ed. Prentice-Hall, 1990.
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