Dinneen, Patrick S. (1904), “laġḋuġaḋ”, in Foclóir Gaeḋilge agus Béarla [Irish and English Dictionary], 1st edition, Dublin: Irish Texts Society, page 413
Ó Dónaill, Niall (1977), “laghdú”, in Foclóir Gaeilge–Béarla [Irish–English Dictionary], Dublin: An Gúm, →ISBN