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