@Article {dfls-isj2020,
    author = {S. {De Capitani di Vimercati} and S. Foresti and
G. Livraga and P. Samarati},
    title = {Towards Owners' Control in Digital Data Markets},
    journal = {IEEE Systems Journal (ISJ)},
    year = {2020},
    note = {to appear}
}