Tan, E-C
Lim, E C P
Ocampo, C E
Allen, J C
Sng, B-L
Sia, A T
Article History
Received: 24 October 2014
Revised: 16 March 2015
Accepted: 26 March 2015
First Online: 12 May 2015
Competing interests
: The authors declare no conflict of interest.