Awdur (Person): Clarke, Julia | Walley, E. E. Manylion y Gyfres: European Environment Vol.8, No.6, November-December 1998, p202-9 Cyhoeddwyd: November 1998 (Diweddariad diwethaf: 01/11/1998)
Awdur (Person): Hillary, Ruth Manylion y Gyfres: European Environment Vol.8, No.6, November-December 1998, p184-92 Cyhoeddwyd: November 1998 (Diweddariad diwethaf: 01/11/1998)