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

Oaxaca GPS Network - OXPL-Putla P.S.
Start: 13-Dec-2006
End: 28-Sep-2007
DeMets, Charles, Cabral-Cano, Enrique, 2007, Oaxaca GPS Network - OXPL-Putla P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T53J3B3W