Since her death, McClintock has been the subject of a biography by the science historian Nathaniel C. Comfort's The Tangled Field: Barbara McClintock's Search for the Patterns of Genetic Control. Comfort's biography contests some claims about McClintock, described as the "McClintock Myth", which he claims was perpetuated by the earlier biography by Keller. Keller's thesis was that McClintock was long ignored or met with derision because she was a woman working in the sciences. For example, when McClintock presented her findings that the genetics of maize did not conform to Mendelian distributions, geneticist Sewall Wright expressed the belief that she did not understand the underlying mathematics of her work, a belief he had expressed towards other women at the time. In addition, geneticist Lotte Auerbach recounted that Joshua Lederberg returned from a visit to McClintock's lab with the remark: 'By God, that woman is either crazy or a genius.' " As Auerbach tells it, McClintock had thrown Lederberg and his colleagues out after half an hour 'because of their arrogance. She was intolerant of arrogance ... She felt she had crossed a desert alone and no one had followed her.'"Comfort, however, asserts that McClintock was well regarded by her professional peers, even in the early years of her career. Although Comfort argues that McClintock was not a victim of gender discrimination, she has been widely written about in the context of women's studies. Most recent biographical works on women in science feature accounts of her experience. She is held up as a role model for girls in such works of children's literature as Edith Hope Fine's Barbara McClintock, Nobel Prize Geneticist, Deborah Heiligman's Barbara McClintock: Alone in Her Field and Mary Kittredge's Barbara McClintock. A recent biography for young adults by Naomi Pasachoff, Barbara McClintock, Genius of Genetics, provides a new perspective, based on the current literature.On May 4, 2005, the United States Postal Service issued the "American Scientists" commemorative postage stamp series, a set of four 37-cent self-adhesive stamps in several configurations.  The scientists depicted were Barbara McClintock, John von Neumann, Josiah Willard Gibbs, and Richard Feynman. McClintock was also featured in a 1989 four-stamp issue from Sweden which illustrated the work of eight Nobel Prize-winning geneticists. A small building at Cornell University and a laboratory building at Cold Spring Harbor Laboratory were named for her. A street has been named after her in the new "Adlershof Development Society" science park in Berlin.Some of McClintock's personality and scientific achievements were referred to in Jeffrey Eugenides's 2011 novel The Marriage Plot, which tells the story of a yeast geneticist named Leonard who suffers from bipolar disorder. He works at a laboratory loosely based on Cold Spring Harbor. The character reminiscent of McClintock is a reclusive geneticist at the fictional laboratory, who makes the same discoveries as her factual counterpart.Judith Pratt wrote a play about McClintock, called MAIZE, which was read at Artemesia Theatre in Chicago in 2015, and was produced in Ithaca NY — the home of Cornell University — in February–March 2018.

Question: How many Nobel prize winners were illustrated on American Scientists" stamps in 1989?
Answer: eight