Cost of installing and operating an electronic clinical decision support system for maternal health care: case of Tanzania rural primary health centres - Saronga, Happiness Pius; Dalaba, Maxwell Ayindenaba; Dong, Hengjin; Sauerborn, Rainer; Sukums, Felix; Blank, Antje; Kaltschmidt, Jens; Loukanova, Svetla (BMC health services research, 2015)