@ARTICLE{CHKK11,
author = {{C}asazza, {P.} and {H}einecke, {A.} and {K}rahmer, {F}. and {K}utyniok,
{G}.},
title = {{O}ptimally sparse frames},
journal = {IEEE J. Inf. Theo.},
year = {2011},
volume = {57},
pages = {7279--7287},
number = {11},
annote = {journal},
url = {http://num.math.uni-goettingen.de/~f.krahmer/CHKK11.pdf}
}