@article{AK07a,
  title="Local Variable Scoping and {K}leene Algebra with Tests",
  author="Kamal Aboul-Hosn and Dexter Kozen",
  note="DOI: 10.1016/j.jlap.2007.10.007",
  year="2007",
  journal="J. Log. Algebr. Program. "
}