Columbia subject headings:
Extravehicular activity (Manned space flight)--History--Chronology.
Manned space flight--Abstracts.
Harvard subject headings:
Extravehicular activity (Manned space flight)--Abstracts.
Extravehicular activity (Manned space flight)--History--Chronology.
Manned space flight--Abstracts.
Princeton subject headings:
Extravehicular activity (Manned space flight)--History--Chronology.