In 'Proceedings of european conference on thermophysical properties, Vienna (Austria), September 24-28, 1990. To be published in 'High temperatures- high pressures'Available at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1990 n.179 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc