Prefixes as 'de la' or 'van', common in European names, are part of the surname. It is advised to always capitalize the prefix, both in the text and in the reference list.
Jean de la Fontaine will be De la Fontaine, J.
Vincent van Gogh will be Van Gogh, V.
Parenthetical citation: (De la Fontaine, 2020; Van Gogh, 2014)
Narrative citation: De la Fontaine (2020) and Van Gogh (2014)
In the reference list, surnames with prefixes are alphabetized by the first letter of the prefix:
De la Fontaine, J. (2020). The fables of La Fontaine. Musée National Gustave Moreau.
Van Gogh, V. (2014). Ever yours: The essential letters (L. Jansen, H. Luijten, & N. Bakker, Eds.). Yale University Press.