On Languages Piecewise Testable in the Strict Sense. - James Rogers; Jeffrey Heinz; Gil Bailey; Matt Edlefsen; Molly Visscher; David Wellcome; Sean Wibel (MOL, 2009)

Cognitive and Sub-regular Complexity. - James Rogers; Jeffrey Heinz; Margaret Fero; Jeremy Hurst; Dakotah Lambert; Sean Wibel (FG, 2012)