Shieh, B.-S., and S.-H. Liang. “Geographic Variations and Temporal Changes in Songs of the Rufous-Capped Babbler Stachyris Ruficeps Praecognita”. Ornis Fennica, vol. 84, no. 4, Dec. 2007, pp. 163–172, https://ornisfennica.journal.fi/article/view/133694.