1.
Jansen H. J.A. Brongers, Air photography and celtic field research in the Netherlands, 2 dln. BMGN-LCHR [Internet]. 1981 Jan. 1 [cited 2022 Aug. 7];96(2):355-6. Available from: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-102427