Importance and performance analysis nasabah produk Takaful Kesehatan Kumpulan : studi kasus pada PT. Asuransi Takaful Keluarga = Importance and performance analysis customer Group Health Takaful products : case study in PT. Asuransi Takaful Keluarga / Handi Surya Adiguna - Handi Surya Adiguna, author (Program Pascasarjana Universitas Indonesia, 2013)