M4 widening : junctions 23 (Magor) to 24 (Coldra) : explanation of the scheme and non-technical summary of the environmental statement = Lledu'r M4 : cyffyrdd 23 (Magwyr) i 24 (Coldra) : esboniad o'r cynllun a chrynodeb annhechnegol o'r Datganiad Amgylcheddol /
Great Britain.Welsh Office.Highways Directorate.
[Cardiff] : Welsh Office,
1995.