APA

Roll-Hansen F., Horntvedt R. & Roll-Hansen H. (1997). On diseases and pathogens on forest trees in Norway 1966-1975. Part II. Abnormal formations. Physiogenic diseases. Diseases due to unknown or complex causes. : .

Chicago

Roll-Hansen Finn, Horntvedt Richard and Roll-Hansen Helga. 1997. On diseases and pathogens on forest trees in Norway 1966-1975. Part II. Abnormal formations. Physiogenic diseases. Diseases due to unknown or complex causes. : .

Harvard

Roll-Hansen F., Horntvedt R. and Roll-Hansen H. (1997). On diseases and pathogens on forest trees in Norway 1966-1975. Part II. Abnormal formations. Physiogenic diseases. Diseases due to unknown or complex causes. : .

MLA

Roll-Hansen Finn, Horntvedt Richard and Roll-Hansen Helga. On diseases and pathogens on forest trees in Norway 1966-1975. Part II. Abnormal formations. Physiogenic diseases. Diseases due to unknown or complex causes. : . 1997.