Helmut Heissenbuttel, Novelist and Poet, 75  Published:
September 22, 1996  Helmut Heissenbuttel, an avant-garde
novelist and postwar-era poet, died on Thursday in a hospital in
this town in northern Germany. He was 75.  The cause was
pneumonia, his wife, Ida, said.  Mr. Heissenbuttel was a leader
in the post-Dada style of literature known as concrete poetry,
an experimental form relying on puns and other wordplay, and not
adhering to rules of grammar and punctuation.  Among Mr.
Heissenbuttel's works are ''Das Textbuch'' (''The Textbook'')
and ''Marlowe's Ende'' (''Marlowe's End''). He received the
coveted Buchner Prize in 1969.  In addition to his wife, he is
survived by three daughters and a son.