Columbia subject headings:
Harvard subject headings:
Comets--Atmospheres--Congresses.
Planets--Ionospheres--Congresses.
Planets--Magnetosphere--Congresses.
Planets--Magnetospheres--Congresses.
Princeton subject headings:
Comets--Atmospheres--Congresses.
Planets--Ionospheres--Congresses.
Planets--Magnetospheres--Congresses.