Cataldo, F., Seeley, J., Nkhata, M. J., Mupambireyi, Z., Tumwesige, E., & Gibb, D. M. (2018). She knows that she will not come back: tracing patients and new thresholds of collective surveillance in PMTCT Option B+. BMC Health Services Research, 18(1), Article 76. https://doi.org/10.1186/s12913-017-2826-7