Cita APA (7a ed.)

Halim, S., Halim, F., & Effendy, S. (2020). Competitive programming 4: The lower bound of programming contests in the 2020s (Cuarta edición.). Lulu.

Cita Chicago Style (17a ed.)

Halim, Steven, Felix Halim, y Suhendry Effendy. Competitive Programming 4: The Lower Bound of Programming Contests in the 2020s. Cuarta edición. Singapore: Lulu, 2020.

Cita MLA (8a ed.)

Halim, Steven, et al. Competitive Programming 4: The Lower Bound of Programming Contests in the 2020s. Cuarta edición. Lulu, 2020.