You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "Other the Celts, name other ways people from Poland are identified.?" whose answer is Germanic, Baltic and Thracian tribes.
Each document should contain about 30 words, and these documents should contain useful information.

Query: common identifiers for people from Poland
Useful Output:

Doc 1: Poland is a Slavic country, located in Central-East Europe. Its culture has changed rapidly since the collapse of the Soviet-controlled communist regime.
Doc 2: Most Polish mitochondrial DNA falls under the groups H1, J1, T, and U5. These mtDNA haplogroups are common in most European and Slavic peoples.
Doc 3: The aim of the present study was to define the mtDNA variability of Polish population and to visualize the genetic relations between Poles.
Doc 4: The built-in Polish Social Security Number (PESEL) data identifier allows false positives for strings that are not valid PESEL numbers.
Doc 5: PESEL (Powszechny Elektroniczny System Ewidencji Ludności) is a unique personal identification number in Poland. It serves as the national