Trusov, A.
[publisher not identified], [date of publication not identified]
Buku Teks
Kay, Adrian.
Edward Elgar, 2006
Buku Teks SO
Walter, Eugene Victor
Chapel Hill, 1988
Buku Teks SO
Baddeley, Alan
Lawrence Erlbaum Associates, 1990
Buku Teks SO
Keith, Arthur, Sir
Watts & Co., 1950
Buku Teks