UMID – Unique Material Identifier (PDF), DigitalPreservationEurope, retrieved 2016-12-27 http://1seminariopreservacaopatrimoniodigital.dglab.gov.pt/wp-content/uploads/sites/19/2015/08/recurso_08.pdf ↩
ST 330:2011 Unique Material Identifier (UMID), SMPTE http://standards.smpte.org/content/978-1-61482-678-1/st-330-2011/SEC1.abstract ↩