In this case, the citation is for an entry in an online reference source without an individual author. The reference work was found within Credo Reference.

Citation Recipe

1. Author.    
2. Title of source.      "Brain."
3. Title of container,    Gale Encyclopedia of Psychology,
4. Other contributors,    edited by Jacqueline L. Longe, 
5. Version,          3rd ed., 
6. Number,
7. Publishers,   Gale,
8. Publication date,   2016,
9. Location.  

Container 2 (in this case the database containing the reference work):

1. Title of container,     Credo Reference,
2. Other contributors,    
3. Version,
4. Number,
5. Publishers, 
6. Publication date,  
7. Location.     search-credoreference-com.ezproxy.ardc.talonline.ca/content/entry/galegp/brain/0.

Example

("Brain" par. 1)

"Brain." Gale Encyclopedia of Psychology, edited by Jacqueline L. Longe, 3rd ed., Gale, 2016. Credo Reference, search-credoreference-com.ezproxy.ardc.talonline.ca/content/entry/galegp/brain/0.