APA (7th ed.) Citation

Twain, M. (1990). The mysterious stranger: A romance. Softdisk.

Chicago Style (17th ed.) Citation

Twain, Mark. The Mysterious Stranger: A Romance. S.l: Softdisk, 1990.

MLA (9th ed.) Citation

Twain, Mark. The Mysterious Stranger: A Romance. Softdisk, 1990.