Dharmavani Bhagavathi Venkatavasu Bokka Himabindu Gurla Stephan Olariu James L. Schwing Time-optimal Tree Computations on Sparse Meshes. 201-220 1997 77 Discrete Applied Mathematics 3 http://dx.doi.org/10.1016/S0166-218X(97)00135-2 db/journals/dam/dam77.html#BhagavathiBGOS97