Image copyright Chris Athanasiou Image caption It is 20 years since Julia Donaldson wrote her best-selling children's story The Gruffalo

Children's authors and illustrators are failing to get recognition, despite huge sales, The Gruffalo writer Julia Donaldson has said.

Speaking at the Hay Festival, she said new books risked going out of print unless the creator had star appeal.

Donaldson has written 200 books, including fiction for young adults and picture books.

But, she said her contemporaries were "certainly not getting the press coverage they deserve".

She added: "There are some great authors and illustrators out there, but because of the way that there are so few bookshops now, and not so many libraries, and that big online companies have taken over, it's a bit much.

"Everything has to be the next big thing or else just go out of print."

Children's books account for a large proportion of total sales and celebrity authors such as David Walliams have helped keep the market buoyant.

But Donaldson said children's books were seldom reviewed in newspapers - leading to a lack of recognition for many - something she would "really like to be remedied".

"In some ways it's a golden age but, unfortunately, lots of authors and illustrators are not getting the recognition they deserve."

Image caption Julia Donaldson said a third of all book sales were children's books

The Hay Festival has staged events to mark anniversaries for some of the UK's best-loved children's books - including The Gruffalo, Elmer the Elephant and We're Going on a Bear Hunt.

Such titles have remained staples for bedtime stories, but other authors are hoping to encroach on a market dominated by modern classics and celebrity authors.

Writer Wendy White, from Kidwelly, Carmarthenshire, won the Tir Na n'Og Award, in 2014 for her book Welsh Cakes and Custard.

White is part of the festival's Writers at Work programme, which gives Welsh authors opportunities to receive tuition from some of the star writers appearing at Hay.

She said a children's book focused on Wales may never reach a best-seller list, but wanted her work to reflect real Welsh lives.

"I think it is really important that children see themselves and their lives reflected in the books that they read," she said.

"If they take part in the school eisteddfod, or they have a mamgu [Welsh grandmother], that's not going to be reflected anywhere else."

Image caption Wendy White says she intends to "carry on writing with a focus on Wales"

White has three children's books published and has written adult fiction under the pseudonym Sara Gethin.

Despite her success, she does not expect her children's books to have high sales figures because of their Welsh subject matter.

"It would be lovely to have a best-seller, especially a best-seller that reflected Wales," she said.

"But, really, I just enjoy writing for children in Wales. I see that they enjoy the books that reflect them, and their lives.

"Whether I sell a hundred copies, 1,000 copies, or more, it doesn't really matter.

"It is just good to know that my books are out there, and that I intend to carry on writing with a focus on Wales."