1. A law of comparative judgement;Thurstone;Psychol. Rev.,1927
2. Likelihood-of-accomplishment scale for a sample of man-machine activities;Blachard,1966
3. A method of predicting human reliability;Pontecorvo;Ann. Reliability and Maintainability,1965
4. Rank correlation methods;Kendall,1948
5. Theory and method of scaling;Torgerson,1967