참고문헌
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- B. H. Chung, Extremal length and geometric inequalities, J. Chungcheong. Math. Soc. 20 (2007), 147-156.
- B. H. Chung, Some applications of extremal length to conformal imbeddings, J. Chungcheong. Math. Soc. 22 (2009), 211-216.