As of June 2020, HeinOnline indexes Digital Object Identifier (DOI) numbers for articles, when available. DOI numbers are displayed below the Author’s name in search results:
![image of Digital Object Identifier in HeinOnline search results](https://help.heinonline.org/wp-content/uploads/2022/04/doi1.jpg)
DOI numbers are also searchable via Advanced Search in the Law Journal Library.
For example, if a user is looking for the article Right to Housing: An Utopia for Wastepickers in the City of Fortaleza-Ceara with reference DOI: 10.19092/reed.v7i1.356, they can look it up by choosing “DOI” from the dropdown and entering the DOI in the corresponding field, and then clicking “search”:
![image of Advanced Search in the Law Journal Library](https://help.heinonline.org/wp-content/uploads/2022/04/doi2.jpg)
The article will be returned as a search result:
![image of search results for DOI search](https://help.heinonline.org/wp-content/uploads/2022/04/doi3.jpg)
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