Voorhis, Jerry
American cooperatives where they come from ... , what they do ..., where they are going ...
Harper & Row, 1961
Buku Teks
Going prime time with live chat reference
Artikel Jurnal
Coffman, Steve
Going live: starting and running a virtual reference service
American Library association, 2003
eBooks
Roles in digital reference
Artikel Jurnal
Heilbroner, Robert L.
Economics explained: everything you need to know about how the economy works and where it's going
Simon & Schuster, 1994
Buku Teks SO