APA Style

al, E., Soemartono, . (1991). Stratification of health centre (a case study) . Surabaya: Puslitbang Yantekkes, Badan Litbangkes.

MLA Style

al, Et., Soemartono, . "Stratification of health centre (a case study)". Surabaya: Puslitbang Yantekkes, Badan Litbangkes, 1991. print.