Gaya APA
Forgelin, R, J.
(1978).
UNDERSTANDING: AN INTRODUCTION TO INFORMAL LOGIC
.
USA:
Harcourt Brace Jovanovich.
Gaya MLA
Forgelin, Robert, J.
"UNDERSTANDING: AN INTRODUCTION TO INFORMAL LOGIC".
USA:
Harcourt Brace Jovanovich,
1978.
Text.