(;AB[dq][jq][ap][bp][cp][co][do][dn]AW[dr][bq][cq][op][qp][bo][bn][cn][ck]C[Black plays.

Source:
     Tesuji Dictionary, by Segoe Kensaku & Go Seigen]SZ[19]

(;B[er]C[Correct, but ...];W[eq]C[... this move looks so good for White that many players might stop reading out this sequence.];B[fq]C[The key follow up.]
(;W[ep]C[With this move, White seems to have some hope, but ...];B[fr]C[... Black calmly connects.]
(;W[dp];B[fo]C[Black's net prevents any escape.   White's corner dies.])
(;W[fp]C[White doesn't have time to run.];B[dp]C[Black easily captures the corner.]))
(;W[dp]C[Capturing the stone leads nowhere.];B[ep]C[White dies.]))
(;B[eq]C[Too slow.];W[br]C[White has at least a ko.  Black can do better.]))