track down

考えてもみませんでしたが，服に限らず大きいサイズの靴も探すのは簡単ではないのですね。trackは「…の（足）跡を追う」などの意味を持つ動詞ですが，track downというPVで「〈物を〉探し出す」という意味をも持ちます（『プログレッシブ英和中辞典』小学館）。
ちなみに言うまでもないかもしれませんが，見出しのHunting for big-footは「大きい足に合う靴を見つけること」の難しさを伝説の生き物を探す難しさに掛けたものだと考えられます。（Koyamamoto）

Hunting for big-foot: Large shoes tough to track down in Tokyo
Buying large shoes in Japan is a bit like trying to find a prime-time TV show that doesn’t feature at least one past or present member of AKB48: You know they exist, but it often takes perseverance and a measure of luck to track them down.
Back home in New Zealand I take a perfectly average size 7, but the corresponding Japanese size of 24.5 definitely puts me at the Bigfoot end of the spectrum. Luckily for me, that’s still within the standard range, but women over 24.5 and men over 27 (9 in U.S., 8 in U.K.) are “outsize,” meaning that a large percentage of the foreign population are going to have problems. And buying shoes online from your favorite store back home can backfire, as the 30-percent import duty on shoes can bump up the total cost considerably.
http://www.japantimes.co.jp/community/2013/06/04/how-tos/hunting-for-big-foot-large-shoes-tough-to-track-down-in-tokyo/#.Ua3oweDxpQI