„27 % of 10-year-olds and 28 % 8-year-olds took extra classes (other than lessons at school) every day or nearly every day.“
Dr. Dorota Strózik u. a., „Children’s Worlds National Report Poland“ (2014), S. 21
„27 % of 10-year-olds and 28 % 8-year-olds took extra classes (other than lessons at school) every day or nearly every day.“
Dr. Dorota Strózik u. a., „Children’s Worlds National Report Poland“ (2014), S. 21