"Amran et al... Fadila et al... Kang... Fernando et al... and Portal et al... produced foamed concrete for use in wall panels. Rum et al... used foamed concrete as a component in a profiled composite slab. Kadela et al.., Drusa et al.., Tian et al... and Lee at al... used foamed concrete in a pavement or floor structure to transmit a load on a subsoil, including weak soil. Moreover, foamed concrete has been used in building foundations..."
January 1, 1970
https://en.wikiquote.org/wiki/Foam_concrete