http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Giáo trình điện tử: Tự học vẽ và thiết kế mạch in với Orcad 9.0 bằng hình ảnh
Phan Quý Võ, Phạm Quang Huy và Huỳnh Minh Đăng
electronic circuit design,arcad ( computer program language )