- Series: Robert E. Howard Letters Series Record # 65557
- Robert E. Howard Letters
- Robert E. Howard: Selected Letters 1923-1930 (1989) [NF] by Robert E. Howard
- Robert E. Howard: Selected Letters 1931-1936 (1991) [NF] by Robert E. Howard
- Dear August: Letters, Robert E. Howard to August Derleth 1932-1936 (2002) [NF] by Robert E. Howard
- Dear HPL: Letters, Robert E. Howard to H. P. Lovecraft 1930-1936 (2002) [NF] by Robert E. Howard
- Drafted: Unsent Letters to H. P. Lovecraft (2013) [NF] by Robert E. Howard
- A Means to Freedom: The Letters of H. P. Lovecraft and Robert E. Howard
- The Collected Letters of Robert E. Howard (First Edition)
- The Collected Letters of Robert E. Howard Volume One: 1923-1929 (2007) [NF] by Robert E. Howard
- The Collected Letters of Robert E. Howard Volume Two: 1930-1932 (2007) [NF] by Robert E. Howard
- The Collected Letters of Robert E. Howard Volume Three: 1933-1936 (2008) [NF] by Robert E. Howard
- The Collected Letters of Robert E. Howard / Index and Addenda (2015) [NF] by Robert Derie and Robert E. Howard [only as by Bobby Derie and Robert E. Howard]
- The Collected Letters of Robert E. Howard (Second Edition)