Nikolai Ellefsen and Hanne Terkelsen

I am looking for information on my grandfather, Nikolai Ellefsen, I have found him on the 1900 census living with his mother, Jorgine Ellefsen, and brother, Helmer Johan Ellefsen in Austre Moland, Sagbakken. After that I can not find information on his emigration to the U.S. I am not sure if he was married in Norway or the U.S. My mother was born in 1910 and my aunt was born in 1908. I am unable to find them in the U.S. census until 1930 when they lived in Camden. N.J. I would like any information on Nikolai Ellefsen and his wife, Hanne Terkelsen. Hanne Terkelsen was born on 12/3/1872, her parents were Johan Severin Terkelsen from Hafstad, Tromoy and his wife Tobine Hellingsdtr. In the 1900 census she was listed as living in Kristiania, but was also listed with her parents in Barbu, Solbakken farm. Thank you for any information.