Cita APA (7th ed.)

Esto, R. (1990). Book of riddles for students & professionals. R.E. Books Marketing.

Cita Chicago (17th ed.)

Esto, Rey. Book of Riddles for Students & Professionals. [S.l.]: R.E. Books Marketing, 1990.

Cita MLA (9th ed.)

Esto, Rey. Book of Riddles for Students & Professionals. R.E. Books Marketing, 1990.