An easy-to-hard effect after nonreinforced preexposure in a sweetness discrimination
Learning & Behavior (2014) - Comment
pubmed: 24853379  doi: 10.3758/s13420-014-0139-9  issn: 1543-4494  issn: 1543-4508 

María Del Carmen Sanjuán, James Byron Nelson, Gumersinda Alonso