| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| The Coexistence of Two Ecolabels: The Nordic Ecolabel and the EU Ecolabel in the Nordic Countries | 978-92-893-2765-7 (92-893-2765-0) | 2014 | Peter Lange · Maja Tofteng |
| The Nordic Swan and Companies: Is it Worthwhile to Acquire the Swan Label? | 978-92-893-2758-9 (92-893-2758-8) | 2014 | Morten Wied · Peter Lange |