Bertinus and Tellete Helgeson (name spelling)

Could I get some help with spelling theses names? I have seen Bertinus, Bertheninus, Bertinius, Berternus Bertinia. And Foletta, Tallate, Tellete for his wife. They were born in Norway 1864/65 and emigrated in 1883. What would the most common spelling be for these two? Thank You