1. http://www.apa.org/helpcenter/willpower.aspx
2. http://www.jneurosci.org/content/36/11/3322.abstract
3. Woods, A. ‘Get excited: reappraising pre-performance anxiety as excitement’, Journal of Experimental Psychology (2013)
4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4359724/