This will fix the PMID parsing issue in articles for which currently

multiple PMID's are getting parsed. Those other id's are likely the PMID's
of cited articles in the article under consideration.
resolves gijswobben#22

pymed/article.py

@@ -47,7 +47,7 @@ def __init__(
                 self.__setattr__(field, kwargs.get(field, None))
 
     def _extractPubMedId(self: object, xml_element: TypeVar("Element")) -> str:
-        path = ".//ArticleId[@IdType='pubmed']"
+        path = ".//PubmedData/ArticleIdList/ArticleId[@IdType='pubmed']"
         return getContent(element=xml_element, path=path)
 
     def _extractTitle(self: object, xml_element: TypeVar("Element")) -> str: