From January 1964 (vol. 31, no. 1), publication increased to six per year, (issued in the odd-numbered months, January, March and so on, but dated "January–February", "March–April", etc.). Volumes again covered two years, so vol. 30, covering 1962–63, therefore included nine issues, ending with the "Winter 1963–64" edition instead of eight. The final edition, vol. 31 no. 12, was published in late 1965.
From January 1964 (vol 31 no 1) publication increased to six per year (issued in the odd-numbered months January March and so on but dated "January–February" "March–April" etc) Volumes again covered two years so vol 30 covering 1962–63 therefore included nine issues ending with the "Winter 1963–64" edition instead of eight The final edition vol 31 no 12 was published in late 1965