The Hall effect, Shubnikov-de Haas effect (SdH), and electrical conductivity have been studied in the temperature range 0.3-4.2 K in magnetic fields up to 8 T in acceptor type graphite intercalated compounds (GICs) of low stages and in low density carbon materials (graphite foils), produced by the thermal destruction of GICs. The parameters of the energy spectrum of carriers were determined. For graphite foils (GFs) the negative magnetoresistance and logarithmic dependence of the electrical conductivity on temperature was found at low temperatures. These data testify to weak localization beyond the diffusion limit.