The learning of basic-level categories by pigeons: the prototype effect, attention, and effects of categorization
Learning & Behavior (2011) - Comment
pubmed: 21484235  doi: 10.3758/s13420-011-0028-4  issn: 1543-4494  issn: 1543-4508 

Masako Jitsumori, Midori Ohkita, Tomokazu Ushitani