San Salvador: Reprocentro, una division de SIGMA, S.A., 1976. Comb-bound octavo (20.5 x 14 cm.), 131, [19] leaves. Index. Facing pages with same numbering. Text in Spanish and English facing. Final unpaginated leaves are lined blanks headed "Notas/Notes". A similarly titled work was issued by the same organization in 1969. It is unclear if this is an updated version of that, and thus a second edition, or if it is.....