APA

Hird J., . (2015). Keynote Proficient WB. : National Geografic Learning.

Chicago

Hird Jon, . 2015. Keynote Proficient WB. : National Geografic Learning.

Harvard

Hird J., . (2015). Keynote Proficient WB. : National Geografic Learning.

MLA

Hird Jon, . Keynote Proficient WB. : National Geografic Learning. 2015.