Adapted from Wikipedia, the free encyclopedia. Internet. Accessed on June 14, 2016.
Karafa MT, Rybicki LA. Biostatistics and Epidemiology. In: Walsh D (ed), Palliative Medicine, Saunders Elsevier, Philadelphia, 2009. P 159.
t-test. IAHPC Pallipedia. https://pallipedia.org/-i-t-i-test/. Accessed