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Noonan, V K
Wolfe, D L
Thorogood, N P
Park, S E
Hsieh, J T
Eng, J J
Article History
Received: 1 October 2013
Revised: 12 February 2014
Accepted: 25 March 2014
First Online: 6 May 2014
Competing interests
: VKN, SEP and NTP were employees of the Rick Hansen Institute at the time this manuscript was written. The other authors declare no conflict of interest.