1. Solar cycle variations of the solar wind;Crooker,1983
2. Interplanetary plasma and magnetic field observations at 1AU;El-Borie,1997
3. Solar cycle variation in the heliosphere;Gazis;Rev. Geophys.,1996
4. Voyager 2 solar wind observations in the outer heliosphere;Lazarus;Space Sci. Rev.,1998
5. Statistical properties of the solar wind;Richardson,1996