And at bedtime she urges parents to follow routines like reading books or telling stories to their children.

VOA: special.2010.06.09

The amount of sleep was based on their reporting of a child's usual bedtime and wake time.

VOA: special.2010.06.09

The study found that children also got less sleep if they did not have bedtime routines.

VOA: special.2010.06.09

Parents know a nightly bedtime is not always easy to enforce.

VOA: special.2010.06.09

But researchers say bedtime rules may improve a child's development.

VOA: special.2010.06.09