Hymnal Noted, parts I & II (New York: Novello, 1851), 131 (Hymn 65 or 30) Google Books
John Mason Neale, Hymni ecclesiae: e breviariis quibusdam et missalibus gallicanis, germanis, hispanis, lusitanis desumpti (Oxford: J.H. Parker, 1851), 57 (Google Books)
Hymns ancient and modern: for use in the services of the church (London: Novello, 1861), hymn #36 (Google Books digitization of the 1867 edition)
hymnsandcarolsofchristmas.com
vid. e.g.: O. Hardwig, ed., The Wartburg Hymnal (Chicago: Wartburg Publishing House, 1918), #78; Andreas Bersagel et al., eds., The Concordia Hymnal (Minneapolis: Augsburg Publishing House, 1932), #118 via Hymns and Carols of Christmas
The English Hymnal (London: Oxford UP, 1906), hymn #8 (see p. 12 of the PDF via IMSLPArchivado el 5 de junio de 2016 en Wayback Machine.)
It is noteworthy that the text is here correctly listed as 18th cent. in origin.
jstor.org
Mother Thomas More, "O Come O Come Emmanuel," The Musical Times 107, no. 1483 (Sept. 1966), 772 JSTOR
Warren Anderson et al, "Hymn," Grove Music Online, Oxford Music Online (Oxford University Press)
theguardian.com
Review of "White as Snow" from the Guardian (13 February 2009)
web.archive.org
The English Hymnal (London: Oxford UP, 1906), hymn #8 (see p. 12 of the PDF via IMSLPArchivado el 5 de junio de 2016 en Wayback Machine.)
It is noteworthy that the text is here correctly listed as 18th cent. in origin.