1. [ACR79a] Ascher, U., Christiansen, J., Russell, R. D., A collocation solver for mixed order systems of boundary value problems, Math. Comp.33, 659–679, 1979.
2. [ACR79b] Ascher, U., Christiansen, J., Russell, R. D., COLSYS—A collocation code for boundary value problems, inCodes for Boundary Value Problems in Ordinary Differential Equations (B. Childs, M. Scott, J. W. Daniel, E. Denman and P. Nelson, eds.), 164–185, Lecture Notes in Computer Science 76, New York, Springer, 1979.
3. [ACR81] Ascher, U., Christiansen, J., Russell, R. D., Collocation software for boundary value ordinary differential equations, ACM Trans. Math. Software7, 209–222, 1981.
4. [AMR88] Ascher, U., Mattheij, R. M. M., Russell, R. D., Numerical Solution of Boundary Value Problems for Ordinary Differential Equations, Prentice-Hall, Englewood Cliffs, New Jersey, 1988.
5. [AO87] Ascher, U., Osborne, M. R., A note on solving nonlinear equations and the ‘natural’ criterion function, J. Opt. Th. Appl.55, 147–152, 1987.