When an artist only makes one copy or print of their work it is called a

The merode altarpiece by robert campin in what way did this painting make art history?

Which does the author mean by " nature had to kindle all the fires, for man by his own effort was unable to produce a spark

In russian churches the number of domes usually matches the number of altars. but this church has only one altar dome, and 21 symbolic ones. what normal construction device does this church lack?