In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: By the 15th century the reach and influence of the Burgundian princes meant that the Low Countries' merchant and banker classes were in the ascendancy. The early to mid-century saw great rises in international trade and domestic wealth, leading to an enormous increase in the demand for art. Artists from the area attracted patronage from the Baltic coast, the north German and Polish regions, the Iberian Peninsula, Italy and the powerful families of England and Scotland. At first, masters had acted as their own dealers, attending fairs where they could also buy frames, panels and pigments. The mid-century saw the development of art dealership as a profession; the activity became purely commercially driven, dominated by the mercantile class.
Burgundian rule created a large class of courtiers and functionaries. Some gained enormous power and commissioned paintings to display their wealth and influence. Civic leaders also commissioned works from major artists, such as Bouts' Justice for Emperor Otto III, van der Weyden's The Justice of Trajan and Herkinbald and David's Justice of Cambyses. Civic commissions were less common and were not as lucrative, but they brought notice to and increased a painter's reputation, as with Memling, whose St John Altarpiece for Bruges' Sint-Janshospitaal brought him additional civic commissions.Wealthy foreign patronage and the development of international trade afforded the established masters the chance to build up workshops with assistants.  Although first-rank painters such as Petrus Christus and Hans Memling found patrons among the local nobility, they catered specifically to the large foreign population in Bruges. Painters not only exported goods but also themselves; foreign princes and nobility, striving to emulate the opulence of the Burgundian court, hired painters away from Bruges.
What were the name of three paintings civic leaders commissioned from major artists?