Digby, Margaret, author
Basil Blackwell , 1956
Buku Teks
Keith, Arthur Berriedale, 1879-1944, author
British Council, 1940
Buku Teks
Grigg, Edward, Sir, author
Liveright Publishing Corporation, 1944
Buku Teks
by Etty Susilowati, Rina Oktaviani, Bustanul Arifin, Yandra Arkeman
Department of Business Management Econom Bogor Agricultural University, 2014
Artikel Jurnal
Giblin, L.F., author
University Press, 1951
Buku Teks