Wei, Z.B., Moldowan, J.M., Peters, K.E., Wang, Y. and Xiang, W. (2007) The Abundance and Distribution of Diamondoids in Biodegraded Oils from the San Joaquin Valley: Implications for Biode-gradation of Diamondoids in Petroleum Reservoirs. Organic Geochemistry, 38, 1910-1926.