University of Tehran Iranian Economic Review 1026-6542 15 29 2011 03 01 The Use Of Financial Ratios as Measures Of Risk In The Determination Of The Bid- Ask Spread In Tehran Stock Exchange 11 25 32720 10.22059/ier.2011.32720 EN Sasan Mehrani Amir Rasaiian Sara Hanjari Journal Article 2013 05 19 https://ier.ut.ac.ir/article_32720_4762f2165b365ce40f1089a20693fe31.pdf