Directorate General for Agriculture & Commission of the European Communities. Directorate-General for Agriculture. (1991). Forest health report 1991: Executive report on the 1990 survey. Office for Official Publications of the European Communities.
Παραπομπή σε μορφή Chicago (17η εκδ.)Directorate General for Agriculture και Commission of the European Communities. Directorate-General for Agriculture. Forest Health Report 1991: Executive Report on the 1990 Survey. Luxembourg: Office for Official Publications of the European Communities, 1991.
Παραπομπή σε μορφή MLA (9th εκδ.)Directorate General for Agriculture και Commission of the European Communities. Directorate-General for Agriculture. Forest Health Report 1991: Executive Report on the 1990 Survey. Office for Official Publications of the European Communities, 1991.