The procedures of creation of ESAI-2006 ADDITION sets are described in papers:
Nagovitsyn Yu A. To the Description of Long-Term Variations in the Solar Magnetic Flux: The Sunspot Area Index. // Astronomy Letters. Vol. 31. No.8. PP. 557-562. 2005.
Nagovitsyn Yu.A. Solar and Geomagnetic Activity on a Long Time Scale: Reconstructions and Possibilities for Forecasts. // Astronomy Letters. Vol. 32. No.5. PP. 382-391. 2006.
Nagovitsyn Yu.A., Makarova V.V., Nagovitsyna E.Yu. Series of classical indices of the Solar activity: Kislovodsk data. // Solar System Research. in print.