Image copyright Getty Images/AP Image caption A raft of celebrities have turned their talents to writing for young people.

The news that former MP and controversial character George Galloway is releasing a series of children's books has taken some in the literary world by surprise.

But he is not the first star to become an unlikely author for youngsters.

Here are nine of the more unexpected celebrities who took on the challenge.

Ricky Gervais

Star of The Office and Extras, Ricky Gervais, is not known for his child-friendly humour. However, the British comedian decided to target a new audience with his "Flanimals" series of books.

Over a million copies have been sold since the first one was published in 2004.

There is even talk of a film, with one of the main strange creatures, Puddloflag, being voiced by Gervais himself.

But in his characteristically self-deprecating fashion, Gervais puts the success of the series down to the books being written by "a man off the telly".

John Travolta

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Think John Travolta and you think sharp suits, the song Grease Lightning and that Pulp Fiction dance sequence with Uma Thurman.

But what you may not know is that Travolta has also tried his hand at appealing to a younger crowd.

In 1997 Travolta wrote "Propeller One Way Night-Coach: A Fable for All Ages" about a little boy who goes on a plane for the first time.

Sadly Travolta's own son Jett died, aged 16, from a seizure during a family holiday in the Bahamas in 2009.

Madonna

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She knows how to strike a pose and vogue, but who knew Madonna was handy with a pen as well?

The musical icon released her first book "The English Roses" in 2003, which incorporated her belief in Kabbalah throughout.

It debuted at number one on The New York Times Bestsellers List for children's picture books and stayed there for 18 weeks.

Her next two books also came in at the top of the famous chart and her sales now go into the millions.

Keith Richards

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Sex, drugs and rock 'n' roll; the saying was made for this Rolling Stone.

However, Keith Richards has a softer side to his stage persona and showed it off in his children's book "Gus & Me: The Story of My Granddad and My First Guitar".

It tells the autobiographical story of how his grandfather - jazz musician Theodore Augustus Dupree - influenced his life.

"I have just become a grandfather for the fifth time, so I know what I'm talking about," he told the New York Times.

"The bond, the special bond, between kids and grandparents is unique and should be treasured. This is a story of one of those magical moments."

Sharon Osbourne

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Another children's author who is more than familiar with the rock 'n' roll lifestyle is TV judge and businesswoman Sharon Osbourne.

The outspoken star - married to veteran rocker Ozzy Osbourne - saw her celebrity status rise when her family took part in an MTV series following their daily lives.

And after voicing a character in the Disney Junior cartoon 'Jake and the Never Land Pirates', she wrote "Mama Hook Knows Best: A Pirate Parent's Favourite Fables" in 2013.

Sharon has said it holds a very strong message for children to listen to their parents.

50 Cent

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Rapper 50 Cent is often found "In Da Club", or perhaps draped in Playboy bunnies.

But don't let this hard exterior fool you - there is a softer side to the man who wrote "Get Rich, or Die Tryin'"

The musician, who was famously shot nine times, wrote a novel called "Playground" in 2011.

The book sets out to teach children about bullying. The rapper - real name is Curtis James lll - has previously admitted that he bullied his schoolmates.

In the book's introduction he wrote: "That's why I wanted to tell this story, to show a kid who has become a bully, how and why that happened, and whether or not he can move past it."

LL Cool J

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What is it with rappers and children's books?

LL Cool J, or "Ladies Love Cool James", beat 50 Cent to the punch with his first children's book, released in 2002.

"And the Winner Is..." was a rap and read book, which the musician hoped would teach lessons to under-10s about humility and sportsmanship.

The book came with a CD to encourage its young readers to rap along with LL.

Sarah Ferguson

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The personal life of the Duchess of York has often been the subject of speculation, with personal relationships and cash flow problems keeping the mother of two in the spotlight.

But Sarah Ferguson also made a name for herself as a children's author.

Her most famous series, beginning in 1989, was "Budgie the Little Helicopter". The books were also turned into an animated television series.

She now has a long list of books to her name, from the "Little Red" series to her latest work, "Ballerina Rosie".

Perez Hilton

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He made his name through catty comments and celebrity blogging, but fatherhood offered Perez Hilton a chance to show another outlook on life.

In September 2011, he published "The Boy With Pink Hair".

"This story is about every kid that's ever had a dream, felt excluded, wanted to belong, and hoped that one day they could do what they loved and make a difference," he said.

Who knows what the Hollywood stars thought of it.