Y. - L.  Qiu, Lee, J., Bernasconi-Quadroni, F., Soltis, D., Soltis, P., Zanis, M., Zimmer, E., Chen, Z., Savolainen, V., and Chase, M. W., ?The earliest angiosperms: evidence from mitochondrial, plastid and nuclear genomes?, Nature, vol. 402, pp. 404-407, 1999.