Sperling, L. E., Steinert, G., Boutter, J., Landgraf, D., Hescheler, J., Pollet, D., et al. (2008). Characterisation of cholinesterase expression during murine embryonic stem cell differentiation. Chemico-Biological Interactions, 175(1-3), 156-160. Retrieved from http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6T56-4SP3SSF-2-5&_cdi=4994&_user=38661&_orig=search&_coverDate=09%2F25%2F2008&_sk=998249998&view=c&wchp=dGLzVlz-zSkzS&md5=c3dbfa53f2a362e39ec3e04560d149c5&ie=/sdarticle.pdf.