Tham khảo Chiều_cao

  1. ↑ Strahler, Alan (2013). Introducing Physical Geography (ấn bản 6). Hoboken, N.J.: Wiley. tr. 42. ISBN 9781118396209. OCLC 940600903. 
  2. ↑ "Note that altitude usually refers to a height in the air (above sea level) and elevation refers to height on the surface [of the Earth] above (or below) sea level." (p.113), Physical Geography, By James F. Petersen, Dorothy Sack, Robert E. Gabler