Inclusion of Sobolev spaces with fractional order

Question

Let $W^{k,p}\mathbb(R^n)$ the usual Sobolev space. We know that if $k>l$ and $1\leq p<q<\infty$, $(k-l)p<n$ and $$\frac{1}{q}=\frac{1}{p}-\frac{k-l}{n}$$ then $$W^{k,p}\mathbb(R^n)\subseteq W^{l,q}\mathbb(R^n)$$ Is this true also if $k,l$ are non integers?