2
|
|
|
|
1
|
3
|
|
Telephone surveys -- Random digit dialing. / https://id.loc.gov/authorities/subjects/sh85133434 : Groves, Robert M.
|
1979
|
1
|
4
|
|
Telephone surveys -- United States -- Methodology. / https://id.loc.gov/authorities/subjects/sh85133433 https://id.loc.gov/authorities/names/n78095330-781 https://id.loc.gov/authorities/subjects/sh99001902
|
2008
|
1
|