Unesco. (1971). The surveillance and prediction of volcanic activity: A review of methods and techniques. Unesco.
Dyfyniad Arddull ChicagoUnesco. The Surveillance and Prediction of Volcanic Activity: A Review of Methods and Techniques. Paris: Unesco, 1971.
Dyfyniad MLAUnesco. The Surveillance and Prediction of Volcanic Activity: A Review of Methods and Techniques. Unesco, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.