Cita APA (7a ed.)

ISTA Mielke GmbH & Mielke, T. (1991). Oil world annual 1991. ISTA Mielke GmbH.

Cita Chicago Style (17a ed.)

ISTA Mielke GmbH y Thomas Mielke. Oil World Annual 1991. Hamburg: ISTA Mielke GmbH, 1991.

Cita MLA (9a ed.)

ISTA Mielke GmbH y Thomas Mielke. Oil World Annual 1991. ISTA Mielke GmbH, 1991.