Johannes Arnesen and Kari Syversdatter

1865 Census Fredrikstad has Johannes Arnesen b. 1811 in Christiania and Karen Syversen b. 1809 in Hedemarken. 1875 Census Fredrkstad has Johannes Arnesen b. 1809 in Christiania and Charn Syversdatter b. 1808 in Vangs. Pr. Where do you think I should look for their birth records? is Vangs Pr in Hedemarken? When Christiania how should you look for records? Thanks!