Botterill, G. S., & Keene, R. D. (1973). The Pirc defence. Cacho Hermanos.
Chicago Style (17th ed.) CitationBotterill, G. S., and Raymond D. Keene. The Pirc Defence. Mandaluyong, Rizal: Cacho Hermanos, 1973.
MLA (9th ed.) CitationBotterill, G. S., and Raymond D. Keene. The Pirc Defence. Cacho Hermanos, 1973.
Warning: These citations may not always be 100% accurate.