NEW YORK (AP) — The next book by primatologist Jane Goodall has been postponed because some passages were lifted from online sources and not properly credited.

Hachette Book Group announced Friday that no new release date has been set for Goodall's "Seeds of Hope," originally scheduled for April 2. Goodall said in a statement that she agreed to delay the book and "correct any unintentional errors."

"It is important to me that the proper sources are credited, and I will be working diligently with my team to address all areas of concern," said Goodall, who has written or co-written more than 20 books.

Hachette said excerpts that appeared this month in Smithsonian magazine did not contain questionable material.

Goodall, 78, co-authored "Seeds of Hope" with Gail Hudson, who has written for Nature, Good Housekeeping and other publications. The book is being billed as a study of "the critical role that trees and plants play in our world."

Earlier this month, a Washington Post freelance reviewer alerted the paper to numerous similarities between material in "Seeds of Hope" and passages on Wikipedia and on websites for organic tea and the history of tobacco.

"My goal is to ensure that when this book is released it is not only up to the highest of standards, but also that the focus be on the crucial messages it conveys," Goodall said. "It is my hope that then the meaningful conversation can resume about the harm we are inflicting on our natural environment and how we can all act together to ensure our children and grandchildren inherit a healthy planet."

Other authors in recent years have used Internet material without attribution, including Chris Anderson, whose 2009 book "Free: The Future of a Radical Price" contained passages taken verbatim from Wikipedia.