<http://www.analog.com/en/products/linear-products/matched-transistors/ssm2212.html><http://www.nxp.com/products/bipolar_transistors/general_purpose_bipolar_transistors/matched_pair_transistors/><http://www.digikey.com/catalog/en/partgroup/npn-transistor-arrays/15467> üdv Vili