Foroughi, Cyrus K.; Serraino, Carolyn; Parasuraman, Raja; Boehm-Davis, Deborah A. (October 2016). "Can we create a measure of fluid intelligence using Puzzle Creator within Portal 2?". Intelligence. 56: 58–64. doi:10.1016/j.intell.2016.02.011. S2CID16707254.
Shute, Valerie J.; Ventura, Matthew; Ke, Fengfeng (August 2014). "The power of play: The effects of Portal 2 and Lumosity on cognitive and noncognitive skills". Computers & Education. 80: 58–67. doi:10.1016/j.compedu.2014.08.013. S2CID15876432.
Coulton, Jonathan (April 29, 2011). "FAQs About the Portal 2 Song". jonathancoulton.net. Archived from the original on May 5, 2011. Retrieved May 20, 2011.
Foroughi, Cyrus K.; Serraino, Carolyn; Parasuraman, Raja; Boehm-Davis, Deborah A. (October 2016). "Can we create a measure of fluid intelligence using Puzzle Creator within Portal 2?". Intelligence. 56: 58–64. doi:10.1016/j.intell.2016.02.011. S2CID16707254.
Shute, Valerie J.; Ventura, Matthew; Ke, Fengfeng (August 2014). "The power of play: The effects of Portal 2 and Lumosity on cognitive and noncognitive skills". Computers & Education. 80: 58–67. doi:10.1016/j.compedu.2014.08.013. S2CID15876432.
Coulton, Jonathan (April 29, 2011). "FAQs About the Portal 2 Song". jonathancoulton.net. Archived from the original on May 5, 2011. Retrieved May 20, 2011.