參考資料

• What is the difference between dpkg and aptitude/apt-get?
• Ubuntu 12.04 Wiki, APT-Get
• Ubuntu 16.04 Wiki, dpkg
• Ubuntu Wiki, AptGet/Howto
• [Wiki, deb (file format)](https://en.wikipedia.org/wiki/Deb_(file_format))
• debian, APT HOWTO(Ch)
• debian, APT User's Guide
• debian, aptitude user's manual
• Ubuntu Wiki, Repositories/CommandLine
• Ubuntu Wiki, SourcesList
• man page of update-alternatives