Profile portraits. According to Vasari - painter's friends: Onofrio (Nofri) Strozzi (Palla Strozzi's son), doctor Girolamo della Valle and lawyer Bonifaccio Frugimelica
<bdi><a href="https://en.wikipedia.org/wiki/en:Andrea_Mantegna" class="extiw" title="w:en:Andrea Mantegna"><span title="Italian Renaissance painter (1431-1506)">Andrea Mantegna</span></a>
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<span class="int-own-work" lang="en">Own work</span> (photo from book)