High all new on here can any one in the art world help me I have a pastel painting the signature on it is nossac it has been done by a fine hand please can you help

Do you have a picture? All I can think of is 'Kossac' but there are three of them.
Wojciech (http://en.wikipedia.org/wiki/Wojciech_Kossak), Juliusz (http://en.wikipedia.org/wiki/Juliusz_Kossak), Jerzy (http://en.wikipedia.org/wiki/Jerzy_Kossak).