Preston F.W. (1948). "The commonness, and rarity, of species". Ecology. ج. 29 ع. 3: 254–283. DOI:10.2307/1930989. JSTOR:1930989.
Papp L., Izsák J. (1997). "Bimodality in occurrence classes: a direct consequence of lognormal and logarithmic series distribution of abundances – a numerical experimentation". Oikos. ج. 79 ع. 1: 191–194. DOI:10.2307/3546107. JSTOR:3546107.
Preston F.W. (1948). "The commonness, and rarity, of species". Ecology. ج. 29 ع. 3: 254–283. DOI:10.2307/1930989. JSTOR:1930989.
Papp L., Izsák J. (1997). "Bimodality in occurrence classes: a direct consequence of lognormal and logarithmic series distribution of abundances – a numerical experimentation". Oikos. ج. 79 ع. 1: 191–194. DOI:10.2307/3546107. JSTOR:3546107.