Gillespie A, Burner T. Principals’ views on the implementation of grade-free middle schools in Norway: justifications, challenges and opportunities. UP [Internett]. 26. november 2019 [sitert 26. april 2024];13(2):21-38. Tilgjengelig på: https://utdanningogpraksis.no/index.php/up/article/view/1969