@misc{ blackburn1998, author = {Blackburn, G. A.}, title = {Spectral indices for estimating photosynthetic pigment concentrations: A test using senescent tree leaves}, journal = {International Journal of Remote Sensing}, publisher = {Taylor & Francis}, pages = {657-675}, volume = {19}, number = {4}, year = {1998} } @misc{ idb, author = {Henrich, V. and Krauss, G. and Götze, C. and Sandow, C.}, title = {The IndexDatabase}, publisher = {}, address = {Bonn}, pages = {}, volume = {}, number = {}, year = {2011} }