Jorgensen, F. a. O. (2023). Cost studies in European forestry. Royal College of Forestry, Stockholm.
Lua i Stíl Chicago (17ú heag.)Jorgensen, Frits and Opheim. Cost Studies in European Forestry. Royal College of Forestry, Stockholm, 2023.
Lua MLA (9ú heag.)Jorgensen, Frits and Opheim. Cost Studies in European Forestry. Royal College of Forestry, Stockholm, 2023.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.