Meanings of educational books in English

As things stand, only educational books may be sold.

She has published a children's book and aspires to write a series of educational books for young readers.

Education consultant, trainer and publisher Howard Campbell has expanded his range of educational books through the open e-book platform BookFusion.

Publishing companies would only agree to a voluntary code of practice on the selling and reprinting of educational books to schools.

To this department may be referred all educational books, the most of them written in rhyme, and according to a system of intellectual gradation.

These advantages are essential for the educational books produced by Campbell and he revealed that he is collaborating with BookFusion on one of his products.

Is there any length to which a publisher won't go to convince parents (uncles, grannies) that children can be persuaded to read educational books?