(See GCCD , Sep 1993) Now analysis of a second ice core (GISP2), drilled near the European one by U.S. scientists, throws the first conclusion into question.
(Now analysis of a second ice core; drilled; near the European one by U.S. scientists; throws the first conclusion into question)
Now analysis of a second ice core
drilled
near the European one by U.S. scientists throws the first conclusion into question