HEFTY, J., and M. IGONDOVÁ. “Diurnal and Semi-Diurnal Coordinate Variations Observed in EUREF Permanent GPS Network – a Case Study for Period from 2004.0 to 2006.9”. Contributions to Geophysics and Geodesy, Vol. 40, no. 3, Dec. 2010, pp. 225-47, doi:10.2478/v10126-010-0010-8.