Vice President Joe Biden’s presidential campaign admitted that some material included in their massive climate change plan was not attributed properly in their document released on Tuesday.

“Several citations were inadvertently left out of the final version of the 22-page document,” the Biden campaign told Business Insider after the campaign ignored conservative media reports about the potential plagiarism problem. “As soon as we were made aware of it, we updated to include the proper citations.”

Some of the phrasing in the Biden plan exactly imitated language from materials produced by the Blue Green Alliance, the Carbon Capture Coalition, and a clean water group American Rivers.

The plagiarism accusations draw more scrutiny to Biden’s campaign after he ended his 1988 presidential campaign because of plagiarism charges.