Gaya APA
Swanson, C, P. (1962).
**Educational achievements of thirteen-year-olds in twelve countries .
Hamburg:
Hamburg: Unesco; 1962.
Gaya MLA
Swanson, Carl, P..
"**Educational achievements of thirteen-year-olds in twelve countries".
Hamburg:
Hamburg: Unesco; 1962,
1962.
Text.