Tone and vowel enhancement in Cantonese infant-directed speech at 3, 6, 9, and 12 months of age. - Nan Xu Rattanasone; Denis Burnham; Ronan G. Reilly (J. Phonetics, 2013)

The perception of Mandarin tones by learners from heritage and non-heritage backgrounds. - Kimiko Tsukada; Hui Ling Xu; Nan Xu Rattanasone (ISCSLP, 2014)