Columbia subject headings:
Cement--Permeability--Congresses.
Cement--Testing--Congresses.
Porosity--Congresses.
Harvard subject headings:
Cement--Permeability--Congresses.
Cement--Testing--Congresses.
Porosity--Congresses.
Princeton subject headings:
Cement--Permeability--Congresses.
Cement--Testing--Congresses.
Porosity--Congresses.