APA (7th ed.) Citation

Wirt, M. A. (2012). The Secret of the Sundial Madge Sterling Series, #3. Project Gutenberg.

Chicago Style (17th ed.) Citation

Wirt, Mildred A. The Secret of the Sundial Madge Sterling Series, #3. Project Gutenberg, 2012.

MLA (9th ed.) Citation

Wirt, Mildred A. The Secret of the Sundial Madge Sterling Series, #3. Project Gutenberg, 2012.

Warning: These citations may not always be 100% accurate.