APA (7th ed.) Citation

Leonardo, d. V., Baring, M., & Einstein, L. (1906). Thoughts on art and life ... [publisher not identified].

Chicago Style (17th ed.) Citation

Leonardo, da Vinci, Maurice Baring, and Lewis Einstein. Thoughts on Art and Life ... Boston, Merrymount Press: [publisher not identified], 1906.

MLA (9th ed.) Citation

Leonardo, da Vinci, et al. Thoughts on Art and Life ... [publisher not identified], 1906.