Gaya APA

al., E. et al (1997,2009,2019). Reliabilitas Dan Validitas (Ed. 3,Ed. 4). Yogyakarta: Pustaka Pelajar Offset.

Gaya MLA

al., Et. et al. "Reliabilitas Dan Validitas". Ed. 3,Ed. 4 Yogyakarta: Pustaka Pelajar Offset, 1997,2009,2019. Text.