Columbia subject headings:
Science--Information services--Europe--Directories.
Technology--Information services--Europe--Directories.
Harvard subject headings:
Information services--Europe--Directories.
Science--Europe--Information services--Directories.
Science--Information services--Directories
Technology--Europe--Information services--Directories.
Technology--Information services--Directories
Princeton subject headings:
Science--Information services--Europe--Directories.
Technology--Information services--Europe--Directories.