His best known work, the "Lament of a Royal Concubine" or "The Complaints of the Royal Harem" (Cung Oán Ngâm Khúc), is an example of song thất lục bát ("double seven, six eight") form of nôm poetry in the ngâm "lament" style.
- Mark W. McLeod, Thi Dieu Nguyen – Culture and Customs of Vietnam – Page 70 2001 "Another famous nom poem employing the ngam style is Cung Oan Ngam Khuc, or the Lament of a Royal Concubine, by Nguyen Gia Thieu (c. 1741— 1798). Nguyen Gia Thieu was an aristocrat related to the Trinh lords. He showed little inclination for officeholding, resigning a command in 1783 and retiring to his lakeside villa in Đông Kinh".
- Norman G. Owen The Emergence Of Modern Southeast Asia: A New History 2005- Page 69 "In the masterpiece of lyric poetry by Nguyen Gia Thieu (1741-1798) "The Complaints of the Royal Harem," the rejected harem women – whom Thieu depicts as accomplished artists and chess players – are surrogates for politically frustrated "