# Set cover with budget on sets

I am wondering if this is a studied variant of the Set Cover problem.

We are given a universe $X$, a collection of sets $S = \{S_1, ..., S_m\}$ and integers $c_i$. We want to cover all elements in $X$ with sets $S'_i \subseteq S_i$ such that $|S'_i| \leq c_i$. In other words we want to cover the elements with as few sets as possible but we are only allowed to use $c_i$ elements of each set.

The most similar variant I found is described in "Maximum Coverage Problem with Group Budget Constraints and Applications"

Thank you

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