Reference in signature

The various notes and coin pages has references as below... what are they refereing to? where we can see those?

P# 26a Signature 1: Abel Beja Corte Real, Francisco José Vieira Machado.

can someone help

If you mean the 'Signature 1' part, that comes from signature lists that are in the 'Standard Catalog of World Paper Money' like this excerpt shows:

This should be discouraged and signatures added in the Numista database so we can have our intern reference like HERE

Yes, the book seems very costly. Internal reference should be there. But I see most of pages it is not the case...

http://www.banknote.ws/ seems to have most of these references... I did not know... Just sharing as it might help someone