1. A. D. Moshkov, Porous Bearing Materials [in Russian], Mashinostroenie, Moscow (1968).
2. N. V. Manukyan, A. K. Pogosyan, Z. A. Manvelyan, and S. A. Malkhasyan, ?Sintered bearing materials for heavy-duty frictional units,? Poroshk. Metall., No. 12, 56?60 (1978).
3. I. V. Kragel'skii, M. N. Dobychin, and V. S. Kombalov, Principles of Friction and Wear Calculations [in Russian], Mashinostroenie, Moscow (1977).
4. Van-Vezer, Phosphorus and Its Compounds [Russian translation], IL, Moscow (1962).