«Classifications that are not based on family trees usually involve ranking languages according to degree of differentiation rather than grouping them; thus, if the Romance languages are compared with Latin, it is seen that by most measures Sardinian and Italian are least differentiated and French most (though in vocabulary Romanian has changed most).» Marius Sala; et al. "Romance languages". Britannica.com.
M. Paul Lewis, "Summary by language size", Ethnologue: Languages of the World, Sixteenth Edition.
glottolog.org
Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, ed. (2023). "Roman". Glottolog 4.8. Jena, Jerman: Max Planck Institute for the Science of Human History.Pemeliharaan CS1: Tampilkan editors (link)