public static async Task <string> FindArticle(string doi)
{
var scihub = await FindAddress();
string text;
try
{
text = await WebUtility.SimpleTextRequest(WebUtility.BuildUrl(scihub, doi));
}
catch (Exception e)
{
throw new SciHubException(SciHubExceptionType.Availability, e);
}
var doc = new HtmlDocument();
doc.LoadHtml(text);
var iframe = doc.GetElementbyId("pdf");
if (iframe != null)
{
var src = iframe.GetAttributeValue("src", string.Empty);
if (src.StartsWith("//"))
{
src = "https:" + src;
}
return(src);
}
throw new SciHubException(SciHubExceptionType.Article);
}