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

Africa Array GPS Network - ASUM-Asumbi P.S.
Start: 14-Dec-2012
End: 03-Feb-2020
Nyblade, Andy, 2015, Africa Array GPS Network - ASUM-Asumbi P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T51J983Q