Question: Are novelists Walter Van Tilburg Clark and Billie Letts both American? 
Related documents: [0]  [DOC] Walter Van Tilburg Clark (August 3, 1909 – November 10, 1971) was an American novelist, short story writer, and educator. He ranks as one of Nevada's most distinguished literary figures of the 20th century, and was the first inductee into the 'Nevada Writers Hall of Fame' in 1988. Two of his novels, "The Ox-Bow Incident" and "The Track of the Cat," were made into films. As a writer, Clark taught himself to use the familiar materials of the western saga to explore the human psyche and to raise deep philosophical issues. [END] 
[1]  [DOC] Billie Dean Letts (née Gipson; May 30, 1938 – August 2, 2014) was an American novelist and educator. She was a professor at Southeastern Oklahoma State University. [END] 
Answer: 
yes
yes