1. Barraclough, J. and Harrison, J.B. (1965), JOCCA, Vol. 48, p. 341.
2. Burkill, J.A. and Mayne, J.E.O. (1988), JOCCA, Vol. 71, p. 273.
3. Gardner, P.J., McAzu, I.W., Barton, V. and Seydt, G.M. (1990), JOCCA, Vol. 73, p. 34.
4. Kalenda, P. (1993), Dyes and Pigments, Vol. 23, p. 215.
5. Kalenda, P. (1999), Acta Mechanica Slovaca, Vol. 3, p. 103.