Yolanda, Industrial Psychologist, South Africa
Elliott Jaques coined the SST. Below some references.
Jaques, Elliott. (1989). Requisite organization: the CEO's guide to creative - Structure and leadership. Arlington, va: Cason Hall & Co.
Jaques, Elliott and Cason, Kathryn. (1994). Human capability: a study of individual potential and its application. Arlington, va: Cason Hall & Co.
Jaques, Elliott and Clement, Stephen D. (1991). Executive leadership: a practical guide to managing complexity. Arlington, va: Cason Hall & Co.