The publisher may have author guidelines on how to cite data. Also, look for examples from previously published papers. The repository or source of the dataset may have suggested citations. 

If there are no recommended data citation models, use DataCite recommendations for the minimum format for citing data:

Required elements

• Creator- Creator or author of the data set
• Publication Year
• Title- Title of the dataset
• Publisher
• Identifier- a unique identifier of the dataset, such as a DOI or a link to the dataset.

Optional elements (as appropriate)

• Version- If a dataset has more than one version, it is important to put the version you used in the citation.
• Resource Type

Recommended forms of a data citation are:

Creator (Publication Year): Title. Publisher. Identifier

Creator (Publication Year): Title. Version. Publisher. Resource Type. Identifier