Brabazon, James, Dorothy L. Sayers: A Biography, Scribner, 1981.

This comprehensive biography includes a foreword by British mystery writer P. D. James.

Rader, Barbara D., and Howard G. Zettler, eds., The Sleuth and the Scholar: Origins, Evolutions, and Current Trends in Detective Fiction, Greenwood Press, 1988.

This is a collection of historical and critical essays on American and English detective fiction.