LINQ XML查询List <object>对象内部的对象未获得正确的结果

Question

我无法正确地从XML查询数据。 问题是要从xml中获取正确的作者列表。

这是XML：

<b:Source xmlns:b=\"http://schemas.openxmlformats.org/officeDocument/2006/bibliography\">
<b:Tag>Paa15</b:Tag>
<b:SourceType>Book</b:SourceType>
<b:Guid>{A718F3A9-395B-40A0-8E01-71E033DF92ED}</b:Guid>
<b:Title>Test title</b:Title>
<b:Year>2015</b:Year>
<b:Publisher>PUB</b:Publisher>
<b:URL>http://www.ee</b:URL>
<b:DOI>123</b:DOI>
<b:Author>
 <b:Author>
  <b:NameList>
    <b:Person>
      <b:Last>LName</b:Last>
      <b:Middle>MName</b:Middle>
      <b:First>FName</b:First>
    </b:Person>
    <b:Person>
      <b:Last>Smith</b:Last>
      <b:First>John</b:First>
    </b:Person>
  </b:NameList>
 </b:Author>
 <b:Editor>
  <b:NameList>
    <b:Person>
      <b:Last>Editor</b:Last>
      <b:First>unknown</b:First>
    </b:Person>
  </b:NameList>
 </b:Editor>
</b:Author>
<b:Pages>5</b:Pages>
<b:RefOrder>2</b:RefOrder>
</b:Source>

对象：

class Citation
{
    public string TypeOfSource { get; set; }
    public string Language { get; set; }
    public List<Author> Author { get; set; }
    public string Title { get; set; }
    public string Year { get; set; }
    public string Publisher { get; set; }
    public string Editor { get; set; }
    public string URL { get; set; }
    public string DOI { get; set; }

}

class Author
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string MiddleName { get; set; }
}

代码：

List<Citation> citationList = new List<Citation>();
        foreach (Source src in citations)
        {
            using (var xmlReader = new StringReader(src.XML))
            {
                var doc = XDocument.Load(xmlReader);
                var result = (from cit in doc.Descendants()
                              where cit.Name.LocalName == "Source"
                              select new Citation
                              {
                                  TypeOfSource = cit.Elements().Where(e => e.Name.LocalName == "SourceType").FirstOrDefault()?.Value ?? "",
                                  Language = cit.Elements().Where(e => e.Name.LocalName == "Language").FirstOrDefault()?.Value ?? "",
                                  Publisher = cit.Elements().Where(e => e.Name.LocalName == "Publisher").FirstOrDefault()?.Value ?? "",
                                  Year = cit.Elements().Where(e => e.Name.LocalName == "Year").FirstOrDefault()?.Value ?? "",
                                  Editor = cit.Elements().Where(e => e.Name.LocalName == "Editor").FirstOrDefault()?.Value ?? "",
                                  URL = cit.Elements().Where(e => e.Name.LocalName == "URL").FirstOrDefault()?.Value ?? "",
                                  DOI = cit.Elements().Where(e => e.Name.LocalName == "DOI").FirstOrDefault()?.Value ?? "",
                                  Title = cit.Elements().Where(e => e.Name.LocalName == "Title").FirstOrDefault()?.Value ?? "",
                                  Author = (from auth in doc.Descendants()
                                            where auth.Name.LocalName == "Author"
                                            select new Author
                                            {
                                                FirstName = auth.Elements().Where(e => e.Name.LocalName == "Author")
                                                .Elements().Where(e => e.Name.LocalName == "NameList")
                                                .Elements().Where(e => e.Name.LocalName == "Person")
                                                .Elements().Where(e => e.Name.LocalName == "First").FirstOrDefault()?.Value ?? "",
                                                LastName = auth.Elements().Where(e => e.Name.LocalName == "Author")
                                                .Elements().Where(e => e.Name.LocalName == "NameList")
                                                .Elements().Where(e => e.Name.LocalName == "Person")
                                                .Elements().Where(e => e.Name.LocalName == "Last").FirstOrDefault()?.Value ?? "",
                                                MiddleName = auth.Elements().Where(e => e.Name.LocalName == "Author")
                                                .Elements().Where(e => e.Name.LocalName == "NameList")
                                                .Elements().Where(e => e.Name.LocalName == "Person")
                                                .Elements().Where(e => e.Name.LocalName == "Middle").FirstOrDefault()?.Value ?? "",
                                            }).ToList()
                              }).FirstOrDefault();
                citationList.Add(result);
            }

正如我所说，选择作者列表有问题。我让两名作者进入列表，但第二位作者的值为空。而且，当我从XML中删除一个人和那个编辑器部分时，我仍然得到两个作者，其中第二个为空。有任何想法我在这里做错了吗？

也许以我在这里所做的方式从XML中选择作者不是最好的方法（最短的方法）？