1. CircStats: Circular Statistics, from Topics in Circular Statistics (2001). R Package Version 0;Agostinelli,2009
2. Studies on habits, habitat and damage of porcupines, Hystrix indica, Rodentia, Mammalia;Ahmad;Pak. J. For.,1977
3. Mammalia II: Erinaceomorpha, Soricomorpha, Lagomorpha, Rodentia;Amori,2008
4. Morphometric variation in the skulls of the crested porcupine Hystrix cristata from mainland Italy, Sicily and northern Africa;Angelici;Mamm. Biol.,2003
5. Bird Display and Behavior;Armstrong,1965