Guzmán-Calderón, Edson
Article History
First Online: 6 May 2016
Compliance with Ethical Standards
:
: The author declares that he has no conflict of interests.
: Edson Guzman-Calderón is the corresponding author. He is responsible for the conception and design, acquisition of data, or analysis and interpretation of data, drafting the article or revising it critically for important intellectual content, and final approval of the version to be published.