20 Alaw gymreig /
detholwyd a golygwyd gan W.S. Gwynn Williams = 20 Welsh melodies : a collection of characteristic Welsh folk-songs, harp-airs, hymn-tunes & dances / selected and edited by W.S. Gwynn Williams.

APA Citation

Gwynn Williams, W. S. (William Sidney). (1950). 20 Alaw gymreig. Llangollen, N. Wales: Gwynn.

MLA Citation

Gwynn Williams, W. S. (William Sidney), 1896-. 20 Alaw Gymreig. Llangollen, N. Wales: Gwynn, 1950.

Warning: These citations may not always be complete (especially for serials).