1.Gaultney, V 2002, Problems of diacritic design for Latin script text faces, UK thesis, SIL International Publications, viewed 1 September 2019, https://www.sil.org/resources/archives/9816.
2.Trương, D 2018, Vietnamese Typography, Donny Trương, viewed 23 July 2019, https://vietnamesetypography.com.
3.Microsoft, 2017, Character design standards - Diacritics for Latin 1, Microsoft, https://docs.microsoft.com/en-us/typography/develop/character-design-standards/diacritics.