Mathematics
Blackboard in <a href="//commons.wikimedia.org/wiki/Tel_Aviv_University" class="mw-redirect" title="Tel Aviv University">Tel Aviv University</a>, <a href="//commons.wikimedia.org/wiki/Israel" class="mw-redirect" title="Israel">Israel</a>, showing lecture in <a href="//commons.wikimedia.org/w/index.php?title=Algebraic_topology&amp;action=edit&amp;redlink=1" class="new" title="Algebraic topology (page does not exist)">algebraic topology</a>.
<b><a href="//commons.wikimedia.org/wiki/User:MathKnight" title="User:MathKnight"><font color="blue">M</font><font color="black">ath</font><font color="green">K</font><font color="black">night</font></a></b> <font color="royalblue" size="3">✡</font> (<a href="//commons.wikimedia.org/wiki/User_talk:MathKnight" title="User talk:MathKnight">Talk</a>) No machine-readable author provided. <a href="//commons.wikimedia.org/wiki/User:MathKnight" title="User:MathKnight">MathKnight</a> assumed (based on copyright claims).
CC BY 2.5
No machine-readable source provided. Own work assumed (based on copyright claims). <span class="int-own-work" lang="en">Own work</span>