Gaya APA
XIX, General Assembly Vancouver, Canada August 9-22 1987. (1987).
Canada:
IUGG.
Gaya Chicago
XIX, General Assembly Vancouver, Canada August 9-22 1987.
.
Canada:
IUGG,
1987.
Text.
Gaya MLA
XIX, General Assembly Vancouver, Canada August 9-22 1987.
.
Canada:
IUGG,
1987.
Text.
Gaya Turabian
XIX, General Assembly Vancouver, Canada August 9-22 1987.
Canada:
IUGG,
1987.
Print.