Preferences for services in a patient’s first six months on antiretroviral therapy for HIV in South Africa and Zambia (PREFER): research protocol for a prospective observational co... oleh Vinolia Ntjikelane, Mhairi Maskew, Prudence Haimbe, Nancy Scott, Allison Juntunen, Pamfred Hasweeka, Linda Sande, Hilda Shakewelele, Priscilla Lumano-Mulenga, Sydney Rosen, Mariet Benade, Mpande Mukumbwa-Mwenechanya