I. Alam, S. Khusro, A. Rauf, and Q. Zaman, “Conducting Surveys and Data Collection: From Traditional to Mobile and SMS-based Surveys”, Pak.j.stat.oper.res., vol. 10, no. 2, pp. 169–187, Aug. 2014, doi: 10.18187/pjsor.v10i2.758.