Volumens
Volumens is a term that may be encountered as a proper noun or as a stylized form in English-language texts to denote more than one volume. It is not a standard English plural of volume, which is volumes. In Latin, the standard neuter noun for "volume" is volumen, with the plural volumina; the suffix -ens in Volumens is not part of classical Latin declension and likely reflects modern coinage or adaptation.
In practice, Volumens can appear in publishing as a title element, in bibliographic catalogs as a stylized
Etymology: Derived from volumen, with stylized Latin-like form. The form Volumens may be used to evoke antiquity
Usage guidance: Use "volumes" when referring to more than one book in ordinary English. Reserve Volumens for