एपीए उद्धरण

Maidl, B. (2008). Hardrock tunnel boring machines. Ernst and sohn.

शिकागो स्टाइल उद्धरण

Maidl, Bernhard...[et.al]. Hardrock Tunnel Boring Machines. Berlin: Ernst and sohn, 2008.

एमएलए उद्धरण

Maidl, Bernhard...[et.al]. Hardrock Tunnel Boring Machines. Ernst and sohn, 2008.