Difficult swamp road construction

Engineering Index Backfile | 1921

Solving Difficult Microtunneling Access Problems Using Drilled Shafts

Carr, T. R. / North American Society for Trenchless Technology | British Library Conference Proceedings | 2000

Difficult subway construction in sand

Monaghan, J.R. / Fitzgerald, Jr., J.J. / Peckworth, H.R. | Engineering Index Backfile | 1933

Difficult construction of concrete sewer

Nicholson, Maury | Engineering Index Backfile | 1910

Difficult sewer construction in Minneapolis

Engineering Index Backfile | 1905