Note that there has to be a "space" between /dotlrn/ and binary ( the same for dotlrn/ source/).
So the correct lines to add to the sources.list file are:
deb http://home.galileo.edu/~solca/dotlrn/ binary/
deb-src http://home.galileo.edu/~solca/dotlrn/ source/
Regards,
Victor Guerra.