skosConcept prefLabel altLabel
http://data.europa.eu/949/concepts/hot-axle-box-detector-direction/rinf/10 
"N"@en
http://data.europa.eu/949/concepts/hot-axle-box-detector-direction/rinf/20 
"O"@en
http://data.europa.eu/949/concepts/hot-axle-box-detector-direction/rinf/30 
"B"@en