Semmens, M. C. (1982). The capacity of some grade-separated roundabout entries. Transport and Road Research Laboratory.
Chicago-viite (17. p.)Semmens, Marie C. The Capacity of Some Grade-separated Roundabout Entries. Crowthorne, Berkshire: Transport and Road Research Laboratory, 1982.
MLA-viite (9. p.)Semmens, Marie C. The Capacity of Some Grade-separated Roundabout Entries. Transport and Road Research Laboratory, 1982.
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