Systems thinking in practice: the current status of the six WHO building blocks for health system strengthening in three BHOMA intervention districts of Zambia: a baseline qualitative study. - Mutale, Wilbroad; Bond, Virginia; Mwanamwenge, Margaret Tembo; Mlewa, Susan; Balabanova, Dina; Spicer, Neil; Ayles, Helen (BMC Health Services Research, 2013)