1. Magnusson, L., Farewell, A., and Nystrom, T., ppGpp: a global regulator in Escherichia coli, Trends Microbiol., 2005, vol. 13, pp. 236–242.
2. Hara, A. and Sy, J., Guanosine 5'-triphosphate, 3'diphosphate 5'-phosphohydrolase. Purification and substrate specificity, J. Biol. Chem., 1983, vol. 258, no. 3, pp. 1678–1683.
3. Carneiro, S., Lourenco, A., Ferreira, E., and Rocha, I., Stringent response of Escherichia coli: revisiting the bibliome using literature mining, Microb. Inform. Exp., 2011, vol. 1, no. 1, p. 14.
4. Jain, V., Kumar, M., and Chatterji, D., ppGpp: stringent response and survival, J. Microbiol., 2006, vol. 44, pp. 1–10.
5. Cashel, M., Gentry, D., Hernández, V., and Vinella, D., The stringent response, tEscherichia coli and Salmonella, Cell. Mol. Biol., Neidhardt, F.C., Ed., Washington, DC, 1996, vol. 1, pp. 1458–1496.