Biederman, Irving; Kirkpatrik-Steger, Kim; Wasserman, Edward (1998). "Effects of Geon Deletion, Scrambling, and Movement on Picture Recognition in Pigeons". Journal of Experimental Psychology: Animal Behavior Processes24 (1): 34–46. PMID9438964. doi:10.1037/0097-7403.24.1.34.
Biederman, Irving; Kirkpatrik-Steger, Kim; Wasserman, Edward (1998). "Effects of Geon Deletion, Scrambling, and Movement on Picture Recognition in Pigeons". Journal of Experimental Psychology: Animal Behavior Processes24 (1): 34–46. PMID9438964. doi:10.1037/0097-7403.24.1.34.
Biederman, Irving; Kirkpatrik-Steger, Kim; Wasserman, Edward (1998). "Effects of Geon Deletion, Scrambling, and Movement on Picture Recognition in Pigeons". Journal of Experimental Psychology: Animal Behavior Processes24 (1): 34–46. PMID9438964. doi:10.1037/0097-7403.24.1.34.
Biederman, Irving; Kirkpatrik-Steger, Kim; Wasserman, Edward (1998). "Effects of Geon Deletion, Scrambling, and Movement on Picture Recognition in Pigeons". Journal of Experimental Psychology: Animal Behavior Processes24 (1): 34–46. PMID9438964. doi:10.1037/0097-7403.24.1.34.