Several sections of potential Republican presidential candidate Dr. Ben Carson's 2012 book America the Beautiful were plagiarized from various sources, BuzzFeed News has found.

In many cases Carson cites the works that he plagiarizes in endnotes, though he makes no effort to indicate that not just the source, but the words themselves, had been taken from different authors.

The case is similar to a 2013 report from BuzzFeed News that found Kentucky Sen. Rand Paul plagiarized in his book while citing the works he copied in the footnotes. Paul's book was eventually updated to include attribution.

In one instance, Carson cites wholesale from an old website that has been online since at least 2002, Socialismsucks.net.

In another example, he plagiarizes from two authors whose works he mentions in passing at earlier points in the book: Cleon Skousen, a conservative historian who died in 2006, and Bill Federer, another conservative historian, who Carson thanks in the acknowledgements for helping get his book published.

Carson's book sold less than 1,000 copies when it was first published in 2012, according to the New York Times' 2013 profile of Carson. After his speech at the National Prayer Breakfast in 2013 exploded on YouTube the book sold 46,000 copies in six weeks, the Times reported.

Carson recently said a decision on a 2016 presidential run is coming before May, and has previously said "the chances are reasonably good" that he will run for president.

In a phone call, Federer told BuzzFeed News he did not care that Carson had copied from his book.

"That's fine," said Federer, who noted his book states he grants permission to duplicate text as long as proper attribution is given.

Federer told BuzzFeed News he had given Carson some of his books when they served together on the board of Regent University.

Besides being a historian, Federer is a former Republican congressional candidate from Missouri. Federer is the author of numerous books, such as Endangered Speeches — How the ACLU, IRS & LBJ Threaten Extinction of Free Speech, and Three Secular Reasons Why America Should be Under God.

"I gave him some of my books, and he was kind enough to give me an acknowledgement," said Federer.

"Permission is granted to duplicate 10,000 words or less, provided acknowledgement is given to" Federer's book, reads a line in the front matter of Federer's book.

Sam Wells, the owner and creator of SocailismSucks.net, confirmed he wrote the text Carson plagiarized in his book.

"The comments at the bottom of the page are mine," he told BuzzFeed News.

Other sources taken nearly verbatim include a CBS News article, a Liberty Institute press release, a local newspaper article, and various internet sites.

In Carson's book, he writes about being caught plagiarizing in college and being given the chance to rewrite the paper after it was discovered.

Not long after that, when I was a psychology major delving into the mysteries of the human mind, I stepped unknowingly into yet another moral dilemma. During my research for one of the papers in an advanced psychology course, I found some passages that seemed particularly appropriate, and I included them in my writing. I did not, however, indicate that this was the work of someone else; frankly, I had never even heard of the term plagiarism. When the professor asked me to make an appointment to discuss my paper, I was befuddled . When I stepped into his office, however, I could immediately sense the weight of the moment. He pointed out that I had plagiarized and told me that the consequences for doing so normally included expulsion. I could see all of my dreams of becoming a doctor dashed by my stupidity. Even though I did not know the implications of plagiarism, I certainly should have known inherently that what I was doing was wrong. I had done it before without consequences and probably would have continued doing it if I had not been caught. Fortunately for me, the professor was very compassionate, realized that I was naïve, and gave me a chance to rewrite the paper. This raises another question: Is ignorance an acceptable excuse for unethical behavior?

"Alongside the author, we too take these matters very seriously. We have been in contact with the author and agent and will work with them to review the given information. We will respond as appropriate," a spokesperson for HarperCollins Christian publishing spokesperson told BuzzFeed News responding on the behalf of HarperCollins and Zondervan, the HarperCollins Christian publishing division which published Carson's work .

Carson's representative Sealey Yates, who functions as his lawyer and literary agent, said they had "begun to review the materials" provided by BuzzFeed News but had "not been able to communicate with the publisher's editorial staff."

"If it is determined that additional citations or attribution are required, the appropriate revisions will be made in subsequent printings," Yates said. "Thank you for bringing this matter to our attention."