1. Report Elevperspektiv No. 7;Andersson B.,1981
2. Andersson B. &Renström L. (1983a).How Swedish pupils age 12–15 explain the copperpipe problem. EKNA‐group Department of Education and Educational Research University of Göteborg Box 1010 S‐431 26 Mölndal Sweden.
3. Andersson B. &Renstrom L.(1983b).How Swedish pupils age 12‐15 explain the exhaust problem. Department of Education and Educational Research University of Göteborg Box 1010 S‐431 26 Mölndal Sweden.