The strong fractional choice number of a graph G is the infimum of those real numbers r such that G is (⌈rm⌉, m)-choosable for every positive integer m. The strong fractional choice number of a family G of graphs is the supremum of the strong fractional choice number of graphs in G. We denote by Q k the class of series-parallel graphs with girth at least k. This paper proves that for k = 4q − 1, 4q, 4q + 1, 4q + 2, the strong fractional number of Q k is exactly 2 + 1 q .
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