Z. Mouradian et I. Soruescaut, THE FLARE PRODUCTIVITY OF THE SUN RELATED TO THE 11-YEAR AND 80-YEAR ACTIVITY CYCLES, Solar physics, 159(1), 1995, pp. 173-179
We studied the productivity of flares and subflares, for the period 19
64 to 1993, according to the Monthly Mean Sunspot Numbers. The results
show that major flares exhibit a cycle of eleven years, while subflar
es follow an 80-year cycle.