%0 Journal Article %A Steven V. Mann %A Robert W. Seijas %T Bid-ask spreads, NYSE specialists, and NASD dealers %D 1991 %R 10.3905/jpm.1991.409381 %J The Journal of Portfolio Management %P 54-58 %V 18 %N 1 %U https://jpm.pm-research.com/content/iijpormgmt/18/1/54.full.pdf