* The name is misspelled or incomplete. There might be a variation of the name or a middle initial missing.
* The artist is relatively unknown. Many talented artists work without achieving widespread recognition.
* The artist's work is specialized. They might be an illustrator, graphic designer, or sculptor working in a specific niche.
To help identify the artist, please provide more information, such as:
* The type of art they create: painting, sculpture, photography, etc.
* The subject matter of their work: landscapes, portraits, abstract, etc.
* Any specific artwork or period of their career: a title, a date, a location where they worked, etc.
With more details, it might be possible to identify the artist "H. Volkmann."