@prefix skos:	<http://www.w3.org/2004/02/skos/core#> .
@prefix isac:	<http://webisa.webdatacommons.org/concept/> .
isac:_letter_	skos:broader	isac:write_message_ .
isac:_book_	skos:broader	isac:write_message_ .
isac:_card_	skos:broader	isac:write_message_ .
isac:_e-mail_	skos:broader	isac:write_message_ .
isac:_email_	skos:broader	isac:write_message_ .