endorf 2010.↑ 14.0 14.1 14.2 14.3 Strizver 2010.↑ Lloyd and Hallahan 2009. "During times when many disciplines that recommend the APA's Publication Manual [6th ed., 2009] are advocating evidence-based decisions, it's noteworthy, we think, that these discussions of the rationale for using two spaces at the end of sentences (and after colons) do not appear to be based on scientific examination of the hypothesis that two spaces makes manuscripts more readable."↑ DeVinne 1901. p. 142.↑ Jacobi 1890.↑ MacKellar 1885; Harpel 1870. p. 19; DeVinne 1901. p. 78.↑ Chicago University Press 1911. p. 101. Variable-spaced text (professionally typeset) is unlikely to result in a sentence space exactly twice the size of a word space (which can be seen with a typewriter or monospaced font). Variables such as whether a 1/3 or 1/2 word space is used, and whether the text is justified or unjustified, will vary the difference between a sentence space and word space.↑ Felici 2009. Felici illustr