<|begin_of_text|><|start_header_id|>system<|end_header_id|>

You are an expert at identifying data availability statements in scientific text. A data availability statement describes where research data can be found or how it can be accessed.<|eot_id|><|start_header_id|>user<|end_header_id|>

Determine if the following text contains a data availability statement. Answer with 'yes' or 'no'.

Text: the authors confirm that all data underlying the findings are fully available without restriction. this research uses data from add health, a program project directed by kathleen mullan harris and designed by j. richard udry, peter s. bearman, and kathleen mullan harris at the university of north carolina at chapel hill. special acknowledgment is due ronald r. rindfuss and barbara entwisle for assistance in the original design. information on how to obtain the add health data files is available on the add health website (http://www.cpc.unc.edu/projects/addhealth/data/restricteduse). to apply for the data, the researcher needs to download the contract application (http://www.cpc.unc.edu/projects/addhealth/data/restricteduse/restrictedusecontract.pdf) and return it to the add health contract administrator (addhealth_contracts@unc.edu).<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>