Temperature dependence of the electrical conductivity in 4, 4′ bis(2-thenylideneamino)biphenyl and 4, 4′ bis(thenyldiphenyl-phosphinylmethyleneamino)biphenyl compounds. - El-Sayed, B.; El-Nawawy, M.; Abd Ellah, E.; Farag, R. (Journal of Materials Science, 1999)