Emigration Lookup-Johan Soderlund

[Margaret Bennett]

Johan/John Soderlund b. 4 July 1843 emigrated to the US in March 1880 (to Boston, MA) according to his naturalization papers. He traveled with his wife, Margarete Christina (Hoglund/Haglund) b. June 1835; a daughter, Ida C. b. 1866; a son, Nils John, b. 1869 possibly in either Gothenberg or Maristad??;and a son, Oscar L. b. 1874.  
Johan/John Soderlund's father is listed as Johannes Benson on his death certificate.
We would like to know the port they sailed from, destination listed, and where in Sweden they were from. Thank you for any help you can provide.

[Simon Duzet]

I have these data for you. Johan Söderlund of Göteborg,36, emigrated to New York on 13 February 1880, alone, sourcecode: 14:81:6888. One Stina Söderlund, 45, of Göteborg, emigrated to Boston on 21 May 1880, alone, no children mentioned.Sourcecode: 15:153:8899. Your people, I guess.

[Margaret Bennett]

Dear Simon,  
Thanks for the information about the Soderlunds. This may be clue I needed. Could you explain what is meant by Sourcecode? I haven't seen it used before.  Could it be from a CD or pertain to a source in Sweden?  
Thanks again, Margaret Bennett