In dictionaries:
Convoy PQ 17
an Allied Arctic convoy during the Second World War.
PQ tree
A PQ tree is a tree-based data structure that represents a family of permutations on a set of elements, discovered and named by Kellogg S. Booth and George S. Lueker in 1976.
Order of battle for Convoy PQ 17
Convoy PQ 18
(2–21 September 1942) an Arctic convoy of forty Allied freighters from Scotland and Iceland to Arkhangelsk in the Soviet Union during the Second World War.
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