APA (7th ed.) Citation
Oliveira, M. A. d., & Oliveira, L. d. (1994). The cork. [publisher not identified],].
Chicago Style (17th ed.) Citation
Oliveira, Manuel Alves de, and Leonel de Oliveira. The Cork. [Portugal?]: [publisher not identified],], 1994.
MLA (9th ed.) Citation
Oliveira, Manuel Alves de, and Leonel de Oliveira. The Cork. [publisher not identified],], 1994.
Warning: These citations may not always be 100% accurate.