Hell, S. W. Department of NanoBiophotonics, MPI for biophysical chemistry, Max Planck Society;
Hell, S. W. (2004). Strategy for far-field optical imaging and writing without diffraction limit. Physics Letters A, 326(1-2), 140-145. Retrieved from http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TVM-4C6XT9X-1-37&_cdi=5538&_user=38661&_orig=browse&_coverDate=05%2F31%2F2004&_sk=996739998&view=c&wchp=dGLbVlz-zSkzS&md5=d2760800c540a10e905e9818dcceef7f&ie=/sdarticle.pdf.