Döös, Marianne, Lena Wilhelmson, Jenny Madestam, and Åsa Örnberg. 2018. “The Principle of Singularity: A Retrospective Study of How and Why the Legislation Process behind Sweden’s Education Act came to Prohibit Joint Leadership for Principals”. Nordic Journal of Comparative and International Education (NJCIE) 2 (2-3):39-55. https://doi.org/10.7577/njcie.2757.