Dealer and collector of USA and world paper money.
http://www.pagescoinsandcurrency.com/

They buy and sell collectable world paper money, stocks and bonds.
http://www.paperm.com/

PCGS Currency is the market leader in third-party grading and authentication, grading nearly 100,000 notes since founded in 2005.
http://www.pcgscurrency.com/

PMG focuses on only one objective, a standard of consistent and accurate grading.
http://www.pmgnotes.com/

Created with the sole purpose of disseminating knowledge about polymer bank notes.
http://www.polymernotes.com/

Reference for polymer bank notes by Stane Straus.
http://www.polymernotes.org/