Is-is-fonds B. - Cyfrolau, cyhoeddiedig ac anghyhoeddiedig / volumes, published and unpublished,

Cyfrolau, cyhoeddiedig ac anghyhoeddiedig, ac eithrio straeon byrion a barddoniaeth. Volumes, published and unpublished, with the exception of short stories and poetry. Trefniant / arrangement: cyfres Bonds of Attachment/Land of the Living series (1971-1991) (B I/1-8); cyfrolau eraill a gyhoeddwyd / other volumes published 1946-1986 (B II/9-23); cyfrolau heb eu cyhoeddi / unpublished volumes (B III/24-25).