Going to scale: design and implementation challenges of a program to increase access to skilled birth attendants in Nigeria. - Okeke, Edward N.; Pitchforth, Emma; Exley, Josephine; Glick, Peter; Abubakar, Isa Sadeeq; Chari, Amalavoyal V.; Bashir, Usman; Kun Gu; Onwujekwe, Obinna; Gu, Kun (BMC Health Services Research, 2017)