Gaya APA

Baker, L., Blass, L. (2017). 21st century communication : listening, speaking and critical thinking . Boston: National Geographic Le: Boston: National Geographic Learning; 2017.

Gaya MLA

Baker, Lida., Blass, Laurie. "21st century communication : listening, speaking and critical thinking". Boston: National Geographic Le: Boston: National Geographic Learning; 2017, 2017. Text.