Links:
[1] https://www.arquitectes.cat/coac-factures
[2] http://www.coac.net/sv/index.jsp
[3] http://www.e-coac.org/07/cacoac/sol_for_fp.asp
[4] http://www.coac.net/coac/internet/IntroducirVerificarFirmas.html
[5] https://www.arquitectes.cat/coac-user-profile-contacte-edit
[6] https://www.arquitectes.cat/ca/printpdf/print/5179