APA Style

Litton, J., Hegbrook, T. (2018). Discover Earth's Secret Holes: The Hidden World (Hardcover (original edition)). London, UK: Little Tiger Press Group.

MLA Style

Litton, Jonathan., Hegbrook, Thomas. "Discover Earth's Secret Holes: The Hidden World". Hardcover (original edition) London, UK: Little Tiger Press Group, 2018. Text.