APA

Sekanin Z., Fry L., . (1991). The Comet Halley archive summary volume. Pasadena, Calif: Jet Propulsion Laboratory, California Institute of Technology.

Chicago

Sekanin Zdenek, Fry Lori, . 1991. The Comet Halley archive summary volume. Pasadena, Calif: Jet Propulsion Laboratory, California Institute of Technology.

Harvard

Sekanin Z., Fry L., . (1991). The Comet Halley archive summary volume. Pasadena, Calif: Jet Propulsion Laboratory, California Institute of Technology.

MLA

Sekanin Zdenek, Fry Lori, . The Comet Halley archive summary volume. Pasadena, Calif: Jet Propulsion Laboratory, California Institute of Technology. 1991.