Copy and paste this citation
B. Walder,
M. R. Tramèr
and R. Blois
(2001).
The effects of two single doses of tramadol on sleep: a randomized, cross-over trial in healthy volunteers. European Journal of Anaesthesiology,
18
,
pp 36-42
doi:10.1046/j.1365-2346.2001.00772.x