People who can't stop: Meet some of the world's oldest workers
As Prince Philip, who turns 96 in June, is to retire from royal duties later this year, we look at some of those people who enjoy their work so much they have decided to carry on - well, most of them a bit longer than the Duke of Edinburgh.
David Goodall, Australia's oldest working scientist
The 103-year-old last year won a battle to keep working on campus at Western Australia's Edith Cowan University in Perth.
Dr Goodall had been ordered to work from home in 2017 amid concerns about his safety, but the university later said "better" office space was found at a campus closer to the scientist's residence.
Dr Goodall, who was earlier forced to give up theatre when his declining vision prevented him from driving to rehearsals, said he was grateful the university was able to accommodate him.
"But I still think the emphasis on safety was unnecessary," he told Australia's national broadcaster ABC.
Dr Goodall, who is now an honorary research associate at the university, has produced more than 100 research papers in an ecology career spanning 70 years.
Anthony Mancinelli, world's oldest barber
The 106-year-old from Orange County, New York state, was officially awarded the title by the Guinness Book of World Records back in 2012.
But Mr Mancinelli, who has been cutting hair for more than nine decades, continues to work.
"Don't stop. If you retire and you are old at anything you're doing - do something else. Don't retire," he said in a recent interview to WCBS 880.
He still fondly remembers early days working in a shop, where barbers would also perform pain-relieving services and even use leeches for high blood pressure therapy.
Granny Mastanamma - YouTube channel sensation from India
The 106-year-old regularly attracts huge numbers of hits on her Country Foods channel.
Using very simple cooking techniques which she describes as "village style", she creates delicious traditional Indian dishes.
Mastanamma, who is from the southern Indian state of Andhra Pradesh, says cooking is not difficult at all, and anyone can do it.
The idea of creating her own channel came after her great-grandson published videos of her cooking with fresh ingredients.
Jack Bertrand Weinstein, US federal judge
The 95-year-old, who works at the Eastern District of New York, assumed senior status in 1993.
However, unlike some other senior judges, he has maintained a full docket.
Asked in 2014 whether he still worked full time, he answered: "Oh, yes, I carry a full load. I carry the same load as any active judge in this court, so when you say how many days I worked, it is seven days. How many days I work in court, it's five. It's a wonderfully exciting job.
"Every morning, when I get up, I can hardly wait to get into the courthouse. There are new questions of law, new questions of fact, many different kinds of people, strange situations."
During World War Two he served in the US Navy, retiring as a lieutenant.
Shigeaki Hinohara - possibly the world's oldest practising physician from Japan
The 105-year-old is often described by his colleagues as Japan's living national treasure.
Dr Hinohara heads five foundations, in addition to being the president of St Luke's International Hospital in Tokyo.
And he still visits the hospital each day and makes a round of his patients.
His father, a Christian clergyman, reportedly gave him valuable advice: "Have big visions and put such visions into reality with courage. The visions may not be achieved while you are alive, but do not forget to be adventurous. Then you will be victorious."
Dr Hinohara has produced thousands of medical papers and written hundreds of books.
Man Kaur - 'miracle from Chandigarh'
The 101-year-old from India stole the show in Auckland, New Zealand last month... by winning the 100m race at the World Masters Games.
She crossed the line in one minute 14 seconds to loud cheers from spectators, taking gold for the 100+ age group (as the only competitor).
Man Kaur, who was cleared to race by doctors, was also down for the shot, javelin and 200m race.