"It is now considered ‘best practice’ to provide a reference to data and software in the same way as researchers routinely provide a bibliographic reference to outputs such as journal articles, reports and conference papers. Citing data and software is one of the key practices leading to recognition of data and software as a primary research output." -- Data Citation (ARDC)
You need to credit the original source of any data you re-use so:
Creators / authors may specify exactly how they want you to attribute their data. If it is unclear or they do not specify you should include the following details where possible:
Data journals feature short data articles that describe data sets and link to full data in repositories. They make it easier for researchers to publish their data and make it accessible.
For more information: ANDS Data Journals Guide
An overview of ANDS investigations of data journals. Webinar also looks at recent initiatives, current examples and future directions of data publishing.