Complex sentence: The label's name was also printed as both "Zang Tumb Tuum" and "Zang Tuum Tumb" on various releases, the word "Tuum" presumably being a contraction of the word "Tuuuum" as featured on the cover of a book by Marinetti.
Split into simpler sentences: The label's name was also printed as both "Zang Tumb Tuum" and "Zang Tuum Tumb" on various releases. The word "Tuuuum" is also featured on the cover of a book by Marinetti.