http://repository.uhamka.ac.id/id/eprint/11285/
BAP+Nilai+Presensi Logic Science of Philosophy Com09
Novi Andayani Praptiningsih, NAP
http://repository.uhamka.ac.id/id/eprint/11285/1/BAP%2BNilai%2BPresensi%20Logic%20%26%20Science%20of%20Philosophy%20COM09.pdf