Mark Levesly. (2021). Cambridge Lower Secondary Science Stage 9: Student's Book. HarperCollins.
Chicago-referens (17:e uppl.)Mark Levesly. Cambridge Lower Secondary Science Stage 9: Student's Book. London: HarperCollins, 2021.
MLA-referens (9:e uppl.)Mark Levesly. Cambridge Lower Secondary Science Stage 9: Student's Book. HarperCollins, 2021.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.