Müller, Jan-Steffen. ”A Density Result for Sobolev Functions and Functions of Higher Order Bounded Variation With Additional Integrability Constraints”. Annales Fennici Mathematici 41, no. 2 (augusti 1, 2016): 789–801. åtkomstdatum maj 20, 2024. https://afm.journal.fi/article/view/135635.