The Church of Jesus Christ of Latter-Day Saints (LDS), also known as the Mormons, has microfilmed thousands of vital records from all over Poland, icluding those presented below for Piotrkow. They are kept in Salt Lake City, UT, USA, Family History Centers in Los Angeles and New York and Museum of Diaspora in Israel, but you can easily order them in your local Family History Centers (click here to find one closest to you) and view them on spot.
Documents are written in Polish and Russian, depanding on the period.
LDS Microfilm Number
Records Types (Births, Marriages, Deaths)
On Permanent Loan
Los Angeles: LA
New York: NY
Beth Hatefutsoth: BH