Gaya APA

Umlas, J, W. (2012). Grateful Leadership : Using the Power of Acknowledgment to Engage All Your People and Achieve Superior Results . USA: Mc Graw Hill.

Gaya MLA

Umlas, Jidith, W.. "Grateful Leadership : Using the Power of Acknowledgment to Engage All Your People and Achieve Superior Results". USA: Mc Graw Hill, 2012. Text.