Lars Sjursen (Louis Severson)

My Grandfather left Bergen 11 july 1901 bound for either the US or Canada. Can anyone help me find the ship name or passenger list for departures that day. He changed his name in the US to Louis Severson from Lars Sjursen, he was born in Leikanger in 1881. My Great Granmother Kristine Larsen left Bergen 2 april 1903 on a prepaid ticket to Minnesopta. Can anyone help me track down this ship or passenger list. Would these voyages have been direct or via the UK? I have tried all the internet sources I can find and nothing shows up. I have information for later years from the US and Canada but can't track the arrivals.