The following information obtained from UNAVCO's online DOI system:
(https://www.unavco.org/data/doi/search/search.html)

RiftVolc GPS Network - HAWA-Hawassa University P.S.
Start: 17-Jan-2013
End: 12-Jan-2020
Biggs, Juliet, Lewi, Elias, 2018, RiftVolc GPS Network - HAWA-Hawassa University P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/XV99-YQ36