Optimum Watchman Routes. - Wei-pang Chin; Simeon C. Ntafos (Inf. Process. Lett., 1988)

Shortest Watchman Routes in Simple Polygons. - Wei-pang Chin; Simeon C. Ntafos (Discret. Comput. Geom., 1991)

The zookeeper route problem. - Wei-pang Chin; Simeon C. Ntafos (Inf. Sci., 1992)