Latin vowels also occurred nasalized. This was indicated in writing by a vowel plus ‹M› at the end of a word, or by a vowel plus either ‹M› or ‹N› before a fricative, as in monstrum /mõːstrũː/.
The following reference is given:
Clackson, James (2008). “Latin”. In Roger D. Woodward. The Ancient Languages of Europe. Cambridge University Press. ISBN 978-0-521-68495-8.
Are the above statements about nasal vowels in Latin entirely uncontroversial?