1983 · W. R. Ditzler, D. Hill, et al. · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · 15
1992 · W. R. Ditzler, D. Hill, et al. · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · 12