APA

Heidinger H., Kitzler H., Zeiner W., World Petroleum Congress (15th. : 1997 : Beijing), Kitzler H. & Zeiner W.Experience with CNG as an environmentally benign transportation fuel. : .

Chicago

Heidinger H, Kitzler H, Zeiner W, World Petroleum Congress (15th. : 1997 : Beijing), Kitzler H and Zeiner W.Experience with CNG as an environmentally benign transportation fuel. : .

Harvard

Heidinger H., Kitzler H., Zeiner W., World Petroleum Congress (15th. : 1997 : Beijing), Kitzler H. and Zeiner W.Experience with CNG as an environmentally benign transportation fuel. : .

MLA

Heidinger H, Kitzler H, Zeiner W, World Petroleum Congress (15th. : 1997 : Beijing), Kitzler H and Zeiner W.: . .