Nur Syasya Sahira M.S., et al. “Instrumen Kualiti Perkhidmatan Industri Takaful: Perbandingan Antara SERVQUAL Dan Piagam Perkhidmatan Pelanggan Takaful”. Journal of Quality Measurement and Analysis, vol. 21, no. 1, Sept. 2026, pp. 321-39, doi:10.17576/jqma.2101.2025.20.