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

RAPID Nevado del Ruiz Volcano GPS Network - BIS0-BIS0_NdR_COL2016 P.S.
Start: 12-May-2017
End: 07-Aug-2017
Dixon, Timothy H., Mattioli, Glen, 2017, RAPID Nevado del Ruiz Volcano GPS Network - BIS0-BIS0_NdR_COL2016 P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5GM8637