I wonder why tunnels are round :
Parker, Steve
I wonder why tunnels are round : and other questions about building / Steve Parker. - London : Kingfisher Publications Plc, c2007. - 32 p : col. ill. ; 29 cm. - I wonder why. .
9780753405222
Buildings.
Earthmoving machinery--Juvenile literature.
Earthmoving machinery.
Questions and answers.
Structural engineering--Juvenile literature.
Structural engineering.
TA 634 / .P37 2007
I wonder why tunnels are round : and other questions about building / Steve Parker. - London : Kingfisher Publications Plc, c2007. - 32 p : col. ill. ; 29 cm. - I wonder why. .
9780753405222
Buildings.
Earthmoving machinery--Juvenile literature.
Earthmoving machinery.
Questions and answers.
Structural engineering--Juvenile literature.
Structural engineering.
TA 634 / .P37 2007