What is insomnia?

What is insomnia?
Tidsskr Nor Laegeforen. 2020 Jan 14;140(1):
Authors: Engstrøm M
PMID: 31948203 [PubMed - in process]

Source: Tidsskrift for den Norske Laegeforening - January 13, 2020 Category: General Medicine Authors: Engstrøm M Tags: Tidsskr Nor Laegeforen Source Type: research