Facebook.Unity.Windows/UnityReferences/2018.xml (11 lines of code) (raw):
  <ItemGroup>
    <Reference Include="UnityEngine">
      <HintPath>$(UNITY_ENGINE_DIR)UnityEngine.dll</HintPath>
    </Reference>
    <Reference Include="UnityEngine.JSONSerializeModule">
      <HintPath>$(UNITY_ENGINE_DIR)UnityEngine.JSONSerializeModule.dll</HintPath>
    </Reference>
    <Reference Include="UnityEngine.CoreModule">
        <HintPath>$(UNITY_ENGINE_DIR)UnityEngine.CoreModule.dll</HintPath>
    </Reference>
  </ItemGroup>