http://kopenhagen.dk/artguide/single/article/sensual-logic/
http://www.electronics-tutorials.ws/logic/logic_10.html
http://www.ee.surrey.ac.uk/Projects/CAL/digital-logic/gatesfunc/index.html#nandgate
http://www.brian-borowski.com/software/truth/
http://www.domi-logic.com/projects/sensual-dynamics/
http://www.148apps.com/app/468052200
http://www.pinterest.com/xiby/sensual-works-by-andr%C3%A9-brito-portuguese-fine-art-p/
http://www.optimaladult.org/index.cfm/linkservid/A88C74EB-5056-A342-4397985CC6CC3058/showMeta/1/
http://en.wikipedia.org/wiki/Metalogic
https://escholarship.org/uc/item/0fj290kv
http://www.sciencedirect.com/science/article/pii/S1568494604001085
http://en.wikipedia.org/wiki/False_(logic)
http://www.bbc.co.uk/schools/gcsebitesize/design/electronics/logicrev2.shtml