Gaya APA

Swanson, C, P., Kerrod, R. (NULL). Encyclopedia of science 2 the heavens stars, galaxies, and the solar ì system . New: New York: Macmillan Pub.Co.; 1991.

Gaya MLA

Swanson, Carl, P.., Kerrod, Robin. "Encyclopedia of science 2 the heavens stars, galaxies, and the solar ì system". New: New York: Macmillan Pub.Co.; 1991, NULL. Text.