Ekvall T, Person L, Ryberg A, Widheden J, Frees N, Nielsen P H, Weidema B P, Wesnæs M – 1998 Life cycle assessment on packaging systems for beer and soft drinks. Main report. Copenhagen: Danish Environmental Protection Agency. (Environmental Project 399)
Ryberg A, Ekvall T, Person L, Weidema B P – 1998 Life cycle assessment on packaging systems for beer and soft drinks. Aluminium cans. Copenhagen: Danish Environmental Protection Agency. (Environmental Project 402)