Gaya APA
Johnson, R, B., Christensen, L. (2020).
Educational research: quantitative, qualitative, and mixed approaches (ed. 7).
California:
Sage Publications.
Gaya MLA
Johnson, R., Burke., Christensen, Larry.
"Educational research: quantitative, qualitative, and mixed approaches".
ed. 7
California:
Sage Publications,
2020.
Buku.