<ref name="Kaspari_et_al_2004">{{cite journal |first1=M. |last1=Kaspari |first2=P. S. |last2=Ward |first3=M. |last3=Yuan |year=2004 |title=Energy gradients and the geographic distribution of local ant diversity |url=https://antcat.org/documents/4466/Kaspari_et_al_2004_Oecologia.pdf |journal=Oecologia (Berlin) |publisher= |volume=140 |issue= |pages=407–413 |doi= }}</ref>