Gaya APA
Walford, A. (1959,1963,1966,1973,).
Walfords Guide To Reference Material 4th.ed Volume 1 (E-Book) .
Great Britain:
The Library Association.
Gaya MLA
Walford, A.J.
"Walfords Guide To Reference Material 4th.ed Volume 1 (E-Book)".
Great Britain:
The Library Association,
1959,1963,1966,1973,.
Text.