best constant and extremals for a vector poincare inequality with weight

Сама статья:

http://wpage.unina.it/tonricci/papers/extremalsjams.pdf

[4]:
http://www.jstage.jst.go.jp/article/fesi/46/2/253/_pdf


[15]:
http://archive.numdam.org/ARCHIVE/ASNSP/ASNSP_1972_3_26_2/ASNSP_1972_3_26_2_391_0/ASNSP_1972_3_26_2_391_0.pdf