K.  De Mulder, Pfister, D., Kuales, G., Egger, B., Salvenmoser, W., Willems, M., Steger, J., Fauster, K., Micura, R., Borgonie, G., and Ladurner, P., ?Stem cells are differentially regulated during development, regeneration and homeostasis in flatworms?, Developmental BiologyDevelopmental Biology, vol. 334, pp. 198-212, 2009.