He published a key paper in 1859, and later a book on the subject.
In 1969 at the age of 13, he published his first paper.
The scientists have not published a paper on their small study.
The next year he published a much longer paper in German on the same subject.
He published 3 books and more than 50 research papers.
He has published more than 280 papers in these areas.
He has published more than 20 books and 100 papers.
He has published a book and papers in this field of social work practice.
He published several papers in the 1920s and 1930s on the subject.
He has published various books and papers on his research.
