OPENINGS -- MATANOVIC, A., ed. Encyclopaedia of chess openings. Vol. A-B. 1978-79. 2 (of 5) vols. Ocl. w. dust-j. -- Id., (a.o.). Keybook. An encyclopaedic analysis of current opening theory. (1983). Obrds. -- P. KERES. Theorie der Schach-Eröffnungen. (1958). 3 vols. Ohcl. w. dust-j. -- I. SOKOLOV. The Ruy Lopez revisited. 2009. Owrps. -- And 23 o. on the subject. (30).