It is important to identify and cite data properly so that others can find the data. It is also important to give credit to the appropriate person/organization.
Example with no author
National Opinion Research Center. General Social Survey, 1977. Conducted by University of Chicago, National Opinion Research Center. ICPSR ed. Ann Arbor, MI: Interuniversity Consortium for Political and Social Research [producer and distributor], 1978. http://doi.org/10.3886/ICPSR07573.v1
Example with a specific author
Gutmann, Myron P. Great Plains Population and Environment Data: Agricultural Data, 1870-1997 [United States]. ICPSR04254-v1.
Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2005-06-22. http://doi.org/10.3886/ICPSR04254.v1