1 D.F. Walls, S.M. Tan, M.J. Holland, and P.. Zoller, in Unknown (World Scientific Publishing Company, Incorporated, Font-Romeu, France, 1992).
1 M.A.M. Marte, P.. Zoller, M.J. Holland, R.. Graham, and D.F. Walls, in (Springer US, Boston, MA, 1992), pp. 41–54.