1. F. Brownell, “Perturbation Theory and an Atomic Transition Model,” Arch. Rat. Mech. & Anal., 10, (1962), p. 149–170.
2. F. Brownell, “Psuedo-Eigenvalues, Perturbation Theory, and the Lamb Shift Computation,” p. 393–423, “Perturbation Theory and its Applications in Quantum Mechanics,” ed. C.H. Wilcox, Wiley, 1966.
3. F. Brownell, “Second Quantization and Recalibration of the Dirac Hamiltonian of a Single Electron Atom without Radiation,” Journ. d’Anal. Math., 16, (1966), p. 1–422.
4. F. Brownell, “A Limbotic Reformulation of Quantum Electrodynamics and the Lamb Shift Basis,” LD00012 monograph, University Microfilm, Ann Arbor, 1973.
5. K. Gustafson & G. Johnson, “On the Absolutely Continuous Subspace of a Self-Adjoint Operator,” Helv. Phys. Acta, 47, (1974), p. 163–166.