Dog ownership, the natural outdoor environment and health: a cross-sectional study - Kruize, Hanneke; Maas, Jolanda; Cirach, Marta; Zilema, Wilma L; Gidlow, Christopher J; Litt, Jill S.; Christian, Hayley; Triguero-Mas, Margarita; Grazuleviciene, Regina; Nieuwenhuijsen, Mark J; Wendel-Vos, Wanda; van den Berg, Magdalena; Andrušaitytė, Sandra (2020)