Ƙirƙirar wani nau'i mai mahimmanci na wannan jumla An gabatar da shi a Ingila a 1991 Ma'aikatar Lafiya (1990).
Tabbas, wani nau'i mai mahimmanci na jumla shine "An gabatar da shi a Ingila a 1991 DEPARTMENT OF HEALTH (1990) Care Program Approach Circular HC (90 ) 23/LASSL (90 ) 11. "