Don’t know how did you set the post type and the taxonomy, but by default I think you’re supposed to see all quotes from an author through myblogname.com/the-author-name.
If you want to place static words such auteur or citation in the link, then this is related to how you set the options for creating the post type and/or the taxonomy. (register_post_type and register_taxonomy).
Note: you can’t use author (in english) because this slug already exists in WordPress (See Reserved terms).
About theme files, when you view a quotes list from an author (a taxonomy in this case), your theme uses taxonomy.php file, you can create this file if doesn’t exists, see Template Hierarchy