Nuget package in Xamarin.Forms project is installed but get missing reference

I'm working on a multiplatform project with Xamarin.Forms in Visual Studio 16.9.2.With the solution Nuget packages manager I installed the SharpFluids package and got no errors or warning.

Now, I can find SharpFluids and other dependecies in the projects dependencies, and also I can see the dlls that Sharpfluids should wrap (CoolProp).

Unfortunately the using SharpFluids directive doesn't work. I get the CS0246 error, namespace not found.

What am I missing?