Mads Melbye, Jan Wohlfahrt, Tine Westergaard, Anne Kristine Valeur Jensen, Anders Koch, Henrik Hjalgrim et al
Melbye M, Wohlfahrt J, Westergaard T, Jensen A K V, Koch A, Hjalgrim H et al.
Births at Christmas are different: population based survey of 2 million deliveries
BMJ 1997; 315 :1654
doi:10.1136/bmj.315.7123.1654