(en) Harry Pettit, « Mystery of the incredibly detailed 3500-year-old sealstone that was found buried with an ancient Greek warrior - and was 1000 years ahead of its time », Daily Mail Online, (lire en ligne)
eurekalert.org
(en) « Archaeologists unearth 'masterpiece' sealstone in Greek tomb », EurekAlert Science News, (lire en ligne)
geologyin.com
(en) « Pylos Combat Agate : Rare Minoan Sealstone Discovered », Geology IN, (lire en ligne, consulté le )
ibtimes.com
(en) Himanshu Goenka, « Pylos Combat Agate, Ancient Greek Seal, Fine Specimen Of Miniature Prehistoric Art », International Business Times, (lire en ligne)