na INLIS000000000002311 20161019134538.0 a ||| | 170609| ||| | 979-526-235-1 0010-011500000000314 001.4 NAS m S.Nasution Metode research Penelitian ilmiah 9 Jakarta Bumi Aksara 2007 Metodologi penelitian 0027/B/b.435/2008