The Act of 12 April 2001 on Elections to the Sejm of the Republic of Poland and to the Senate of the Republic of Poland
Journal of Laws of the Republic of Poland, No 46, item 499, of 16 May, 2001 and No.154, item 1802 of 29 December, 2001.
The link address is: http://www.legislationline.org/documents/id/4543