Srivastava, B., Nguyen, X., Kambhampati, S., Do, M. B., Nambiar, U., Nie, Z., Nigenda, R. and Zimmerman, T. (2001) “AltAlt: Combining Graphplan and Heuristic State Search”, AI Magazine, 22(3), p. 88. doi: 10.1609/aimag.v22i3.1579.