This includes 16 books, all Dutton editions.

11 novels in Hardcover: An Academic Question, Crampton Hodnet, Excellent Women, A Few Green Leaves, A Glass of Blessings, Jane and Prudence, Less Than Angels, No Fond Return of Love, Quartet in Autumn, Some Tame Gazelle, An Unsuitable Attachment

Plus, in Hardcover: 
Civil to Strangers and Other Writings
A Very Private Eye, Pym's Autobiography in Diaries and Letters
A Lot to Ask: A Life of Barbara Pym by Hazel Holt
The Barbara Pym Cookbook by Hilary Pym and Honor Wyatt

Bonus Paperback: The Sweet Dove Died