In a commentary in The Lancet, Margaret Whitehead and Paula Holland of the University in Liverpool said further research is needed.

BBC: 'Suicide risk' for lone parent kids

The World Database of Happiness, which is run out of Erasmus University in Rotterdam, Holland, counts 7, 494 names in its Directory of Happiness Investigators--published academics or research groups every one.

FORBES: Magazine Article

Prince Willem-Alexander, 45, was educated in Wales and Holland where he earned a history degree at Leiden University.

CNN: STORY HIGHLIGHTS

Prince Willem-Alexander was educated in Wales and Holland, where he earned a history degree at Leiden University.

CNN: Dutch queen prepares to hand throne to son