1. H. M. Mott-Smith, Massachusetts Institute of Technology, Lincoln Laboratory Group Report V-2 (1954), pp. 39–50.
2. Eigenvalues and Eigenfunctions of the Linearized Boltzmann Collision Operator for a Maxwell Gas and for a Gas of Rigid Spheres.
3. G. E. Uhlenbeck and C. S. Wang Chang, Engineering Research Institute, University of Michigan, Ann Arbor, Project M999 (1952).
4. G. E. Uhlenbeck and C. S. Wang Chang, Engineering Research Institute, University of Michigan, Ann Arbor, Project M999 (1953).