Rusfidra, et al. “Characterization of Number of Crow and Qualitative Marker of Kokok Balenggek Song Fowl Inside a Captive Breeding Farm in Solok Regency, West Sumatera Province, Indonesia”. International Journal of Poultry Science, vol. 13, no. 6, May 2014, pp. 343–346, https://doi.org/10.3923/ijps.2014.343.346.