Cita APA (7a ed.)

Portland Cement Association. Continous hollow girder concrete bridges. Portland Cement Association.

Cita Chicago Style (17a ed.)

Portland Cement Association. Continous Hollow Girder Concrete Bridges. Illinois: Portland Cement Association.

Cita MLA (9a ed.)

Portland Cement Association. Continous Hollow Girder Concrete Bridges. Portland Cement Association.

Precaución: Estas citas no son 100% exactas.