DJVU PDF Costello, N. 2001, "Aspect and tense in Katu of the Lao PDR", in The Mon-Khmer Studies Journal, vol. 31, pp. 121-125. cite.
DJVU PDF Costello, N. 2000, "Dialect differences for Katu prepositional phrases", in The Mon-Khmer Studies Journal, vol. 30, pp. 65-73. cite.
DJVU PDF Costello, N. 1998, "Affixes in Katu of the Lao P.D.R", in The Mon-Khmer Studies Journal, vol. 28, pp. 31-42. cite.
DJVU PDF Costello, N. 1998, "Fire and water in Mon-Khmer mythology", in The Mon-Khmer Studies Journal, vol. 28, pp. 150-151. cite.
DJVU PDF Costello, N. and Sulavan, K. 1996, "Preliminary statement of Katu orthography in Lao script", in The Mon-Khmer Studies Journal, vol. 26, pp. 233-244. cite.
DJVU PDF Costello, N. 1969, "The Katu noun phrase", in The Mon-Khmer Studies Journal, vol. 3, pp. 21-35. cite.
DJVU PDF Costello, N. 1966, "Affixes in Katu", in The Mon-Khmer Studies Journal, vol. 2, pp. 63-86. cite.