<|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: all the data for this study was obtained from previously published papers. (massa p, avesani p. controversial users demand local trust metrics: an experimental study on epinions. com community. in proceedings of the national conference on artificial intelligence. menlo park, ca; cambridge, ma; london; aaai press; mit press; 2005, 20(1): 121.). readers can contact the authors of those papers at (massa@itc.it) to obtain the data.<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>