@article{pea-mil-92-bioseq, author = {William R. Pearson and Webb Miller}, title = {Dynamic Programming Algorithms for Biological Sequence Comparison}, journal = {Methods in Enzymology}, volume = {210}, pages = {575--601}, year = 1992, comment = {Credits Needleman and Wunsch~\cite{nee-wun-70-bioseq} as the first to use PD for biosequence comparison. They point out that although the time is $\Theta(N^2)$, the space required is only $\Theta(N)$.} }