1. Association of Hong Kong Agencies for Migrant Workers Limited. (2017). Statistic of Foreign domestic helpers. Retrieved April 4, 2018, from http://ahka.org/statistic-of-foreign-domestic-helpers.html
2. Bacon-Shone, J., & Bolton, K. (2008). Bilingualism and multilingualism in the HKSAR: Language surveys and Hong Kong’s changing linguistic profile. In K. Bolton & H. Yang (Eds.), Language and society in Hong Kong (pp. 25–51). Open University of Hong Kong Press.
3. Bacon-Shone, J., & Bolton, K. (2013). A study on the use of language in the workplace of Hong Kong. Social Sciences Research Centre, The University of Hong Kong. Retrieved at May 15, 2018 from http://www.trp.hku.hk/files/language_2/A_Study_on_the_Use_of_Language_in_the_Workplace_Full_May15.pdf
4. Bacon-Shone, J., Bolton, K., & Luke, K. K. (2015). Language use, proficiency and attitudes in Hong Kong. Social Sciences Research Centre, The University of Hong Kong. Retrieved at May 18, 2018 from http://www.ssrc.hku.hk/files/language_2/HK_lg_survey_Final.pdf
5. Bolton, K. (2002). Asian Englishes today: Hong Kong English autonomy and creativity. Hong Kong University Press.