Wallis, Ian R., Edwards, Melanie J., Windley, Hannah, Krockenberger, Andrew K., Felton, Annika, Quenzer, Megan, Ganzhorn, Joerg U., and Foley, William J. (2012) Food for folivores: nutritional explanations linking diets to population density. Oecologia, 169 (2). pp. 281-291.