_:n18da53587b844cd2bbc4deb3265a4cf4xb5
<http://schema.org/isAccessibleForFree>
<https://link.springer.com/article/10.1007/s12134-018-0602-0?error=cookies_not_supported&code=66f78ca5-5ac8-49ce-9702-1e3272323fb9>