1. Anon. 1982.Återväxttaxeringen 1982, 19Sweden: National Board of Forestry. (In Swedish)
2. Anon. 1985.SAS/STAT guide for personal computers, Version 6th edition, 941Cary, NC: SAS Institute Inc. USA
3. Anon. 1988.The Forestry Act, Instructions, 115Sweden: National Board of Forestry. (In Swedish)