C. Winarti,, - and A. Cari,, - and I. Suparmi,, - and J. Budiarti,, - and H. Handhika & V. Viyanti, - (2017) Identification of consistency and conceptual understanding of the Black principle. Taylor & Francis Group, London,. pp. 249-252. ISSN ISBN 978-1-138-05343-4