Kumpulan Daftar Isi Buku 614.4 WEB e (RS) Essential... : Muddied waters: the challenge of confounding. ( Ket. Lihat halaman 197-220 ) ( Bab. 8 ) Webb, Penny; Bain, Chris New York: Cambridge university press, 2011 https://lib.fkm.ui.ac.id:443/detail?id=95863