edited by Kjell Erik Rudestam, Judith Schoenholtz-Read
Sage, 2002
Buku Referensi
edited by Kjell Erik Rudestam and Judith Schoenholtz-Read
Sage, 2002
Buku Referensi
Rockart, John Fralick
McGraw-Hill, 1975
Buku Teks
edited by Heather Fry, Steve Ketteridge and Stephanie Marshall
Routledge, 2009
Buku Referensi
Ramsden, Paul
Routledge , 1992
Buku Teks