Algorithm 592: A FORTRAN Subroutine for Computing the Optimal Estimate of f(x). - P. W. Gaffney (ACM Trans. Math. Softw., 1983)

NITPACK: An Interactive Tree Package. - P. W. Gaffney; J. W. Wooter; K. A. Kessel; W. R. McKinney (ACM Trans. Math. Softw., 1983)

Algorithm 606: NITPACK: An Interactive Tree Package. - P. W. Gaffney; J. Wooten; K. A. Kessel; W. R. McKinney (ACM Trans. Math. Softw., 1983)

Algorithm 687: a decision tree for the numerical solution of initial value ordinary differential equations. - Cliff A. Addison; Wayne H. Enright; P. W. Gaffney; Ian Gladwell; P. M. Hanson (ACM Trans. Math. Softw., 1991)