1. The productivity of several machines under the care of one operator;Ashcroft;J. Roy. Stat. Soc. B,1950
2. The productivity of machines requiring attention at random intervals;Benson;J. Roy. Stat. Soc. B,1951
3. Machine Interference;Benson,1957
4. The efficiency of bi-directionally traversed machines;Bunday;J. Roy. Stat. Soc. C,1973
5. The efficiency of N machines uni-directionally patrolled by one operative when walking time and repair times are constants;Mack;J. Roy. Stat. Soc. B,1957