.Langley, B. C. (1991). High-Efficiency gas furnace troubleshooting handbook. Prentice-hall, Inc.
芝加哥风格引文.Langley, Billy C. High-Efficiency Gas Furnace Troubleshooting Handbook. New jersey: Prentice-hall, Inc, 1991.
MLA引文.Langley, Billy C. High-Efficiency Gas Furnace Troubleshooting Handbook. Prentice-hall, Inc, 1991.
警告：这些引文格式不一定是100％准确.