期刊之家：学术期刊变动咨询
期刊之家：学术期刊的家园，这里分享学术期刊发展收稿情况与排版刊期情况
Sigma Corporation of America is a subsidiary of the Sigma Corporation, a Japanese based family owned manufacturer of DSLR cameras, camera lenses and camera accessories. Founded in 1961, Sigma Corporation prides itself on high quality and innovative photographic equipment.
