Based on the clue 'a series of connected spirals', what is the answer?

Based on the clue 'a series of bulgarian stamps featuring types of th...', what is the answer? Based on the clue 'a series of canals links the volga river to this s...', what is the answer? Based on the clue 'a series of childrens books by laura lee hope feat...', what is the answer? What is associated with: a series of comebacks highlights his life including election to a final stint as british pm at… Based on the clue 'a series of decorative grooves on an architectural...', what is the answer? Based on the clue 'a series of dreams he had about lions helped inspi...', what is the answer? Based on the clue 'a series of engraved letters on stone from the lat...', what is the answer? Based on the clue 'a series of events resulting from one act or event...', what is the answer?