( ( These readings ) ( ( ( ( have ( spanned ( dates ( for ( ( many four ) ( year periods ) ) ) ) ) ) and ) ( have ( spanned ( beyond ( the ( larger ( ( 52 year ) cycle ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT These) (NNS readings)) (VP (VP (VBP have) (VP (VBN spanned) (NP (NP (NNS dates)) (PP (IN for) (NP (ADJP (JJ many) (NP (CD four))) (NN year) (NNS periods)))))) (CC and) (VP (VBP have) (VP (VBN spanned) (PP (IN beyond) (NP (DT the) (JJR larger) (ADJP (CD 52) (NN year)) (NN cycle)))))) (. .)))
These readings have spanned dates for many four year periods and have spanned beyond the larger 52 year cycle.
(ROOT (S (NP (NNS Cells)) (VP (VBP have) (NP (CD four) (NNS cycles))) (. .)))