Could it have been collected by a government agency?
A nonprofit/nongovernmental organization?
A private business or industry group?
2. Look for publications that cite the dataset
e.g. scholarly articles or government reports.
3. Once you know that what you want exists, it's time to hunt it down.
Is it freely available on the web? Check Google—you never know!
Or part of a package to which the library already subscribes?
Can it be requested directly from the researcher? There’s a reason articles usually include author contact information
What is the difference between a dataset and a study?
A dataset is a building block of a data collection or study. It is a file containing cases or observations, and the data collected for each case are presented in a grid format.
A study is a detailed investigation and analysis of subjects or situations. It is a collection of data containing one or more datasets, as well as codebooks, data collection instrument files, reports, and other related materials, associated with each dataset.