Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field Subject Field/52
Is Reference of Πισσούχος σχιστόλιθος-el#Sense
Oil shale-en#Sense
Argillite petrolifera-it#Sense
Schiste bitumineux-fr#Sense
Pizarra bituminosa-es#Sense
Olie in kleilagen-nl#Sense
Palavakivi-fi#Sense
Olieskifer-da#Sense
Ölschiefer-de#Sense
Xistos betuminosos-pt#Sense