Columbia subject headings:
Harvard subject headings:
Catastrophes (Mathematics)--Congresses.
Modality (Linguistics)--Congresses.
Semiotics--Congresses.
Thom, René, 1923-2002--Congresses.
Princeton subject headings:
Catastrophes (Mathematics)--Congresses.
Modality (Linguistics)--Congresses.
Semiotics--Congresses.
Thom, René, 1923-2002--Congresses.