【踏破铁鞋】〖tà pò ti xié〗[wear out iron shoes -- spare no effort in searching for sth]

踏步不前修资返，

破产荡业公厂关。

铁杵成针诗典著，

鞋帮穿底举维艰。

比喻为找某种东西历尽困难，花费极大的力气。Metaphor look for something calendar all difficulties, spend extremely strength.