T. Ackemann, J. Seipenbusch, B. Berge, B. Schäpers, Y. A. Logvin, and W. Lange, "Drift instability and locking behavior of two-dimensional optical patterns,"
in Quantum Electronics and Laser Science Conference, J. Bokor, R. Slusher, P. Bucksbaum, and R. Falcone, eds.,
Vol. 12 of OSA Technical Digest
(Optical Society of America, 1997), paper QWD38.