Gaya APA
Hopton, David. (1983).
Payment Systems .
Illinois:
s.n..
Gaya Chicago
Hopton, David.
Payment Systems.
Illinois:
s.n.,
1983.
Text.
Gaya MLA
Hopton, David.
Payment Systems.
Illinois:
s.n.,
1983.
Text.
Gaya Turabian
Hopton, David.
Payment Systems.
Illinois:
s.n.,
1983.
Print.