-
1Trafodyn Cynhadledd LlyfrCyhoeddwyd 1991“...American Society of Mechanical Engineers. Environmental Control Division...”
-
2Trafodyn Cynhadledd LlyfrCyhoeddwyd 1995“...American Society of Mechanical Engineers. Environmental Control Division...”
-
3Trafodyn Cynhadledd LlyfrCyhoeddwyd 1996“...American Society of Mechanical Engineers. Environmental Control Division...”