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: Albrecht the Elder was 62 or 63  when his panel was painted early in 1490. Barbara's portrait may have been completed soon after, when she would have been around 39. Their son was around 18 and had just completed his apprenticeship with Michael Wolgemut, and would soon leave for Nuremberg to travel as a journeyman painter. The father panel was painted first; for aesthetic reasons Dürer may have waited a year or two until his mother looked older.The sitters are presented in three-quarter view before flat, nondescript lacquer-like green backgrounds, which although lushly coloured, are thinly layered. Each has a white ground and light red imprimatura with lead content. The sitter's form and pose echo and in many ways counterbalance each other. Brand Philip draws attention to the similarities of the panels' linear construction, especially the manner in which the folds and lines of their clothing form triangular shapes. The train of Barbara's headdress across her chest corresponds with the opening of Albrecht's fur-lined coat. It was more usual in pendant portraits of this type for the male to be on the left-hand side; the positioning here may be an indication that Dürer originally intended his father's panel to stand alone, given that Barbara's was painted some time later.Albrecht the Elder's panel is regarded as the superior of the two works. This may in part be attributed to differing contemporary treatments of male and female portraits; men were allowed more individuality, while female portraits were bound by stereotypes and were not as daring, for example showing evidence of ageing. In either case, the father painting is far more closely detailed, especially in the lining of clothing, which is summary in Barbara's panel, compared to the long seam of her husband's gown. This contrast in detail can also be seen in the treatment of the rosaries, which are given prominence and a glowing red colour in his panel, but are small and relegated in hers.Albrecht the Elder's panel is usually, but not always, thought to be the first of the two to be executed and, if so, is the earliest extant example of his son's painting. In contrast, a number of art historians have noted that his mother's portrait contains bland passages, especially around the eyes and may be a near-contemporary copy of a lost original. Lotte Brand Philip believes the clumsiness in the mother panel indicated that Dürer painted it first, as a youthful attempt at portraiture, and that Albrecht the Elder might have later "commissioned" his own portrait to pair with Barbara's. Recent technical examination of the two panels confirms that Barbara's portrait was painted later than her husband's.
What is the name of the person that completed his apprenticeship with Michael Wolgemut?