Cita APA (7a ed.)

Aceñolaza, F. G., & Baldis, B. A. J. (1987). The ORDOVICIAN system of South America: Correlation charts and explanatory notes. IUGS.

Cita Chicago Style (17a ed.)

Aceñolaza, Florencio Gilberto, y Bruno Alberto Juan Baldis. The ORDOVICIAN System of South America: Correlation Charts and Explanatory Notes. S.L.: IUGS, 1987.

Cita MLA (8a ed.)

Aceñolaza, Florencio Gilberto, y Bruno Alberto Juan Baldis. The ORDOVICIAN System of South America: Correlation Charts and Explanatory Notes. IUGS, 1987.