Allan 1986 Allan, Nigel (Avgust 1986). »Accessibility and Altitudinal Zonation Models of Mountains«. Mountain Research and Development. International Mountain Society. 6 (3): 185–194. doi:10.2307/3673384. JSTOR3673384.
Hemp 2006 Hemp, Andreas (Maj 2006). »Continuum or Zonation? Altitudinal Gradients in the Forest Vegetation of Mt. Kilimanjaro«. Plant Ecology. 184 (1): 27. doi:10.1007/s11258-005-9049-4.
jstor.org
Stadel 1990 Stadel, Christoph (Oktober 1990). »Altitudinal Belts in the Tropical Andes: Their Ecology and Human Utilization«. V Tom L. Martinson (ur.). Conference of Latin Americanist Geographers, Benchmark 1990. Auburn, Alabama. str. 45–60. JSTOR25765738.
Allan 1986 Allan, Nigel (Avgust 1986). »Accessibility and Altitudinal Zonation Models of Mountains«. Mountain Research and Development. International Mountain Society. 6 (3): 185–194. doi:10.2307/3673384. JSTOR3673384.