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

Africa Array GPS Network - MTVE-MTWARA P.S.
Start: 11-Aug-2011
End: 14-Feb-2018
Nyblade, Andy, 2012, Africa Array GPS Network - MTVE-MTWARA P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5N014MT