All efforts of mediation by a thirdparty were in vain at all.
第三方所作的从中调解的一切努力均告失败。
《新英汉大辞典》
2
Child custody mediation is a process in which parents work together to develop a plan for parenting their children after divorce with the help of a neutral thirdparty.
单亲孩子的看护是指，在一个中立的第三方的帮助下，为了解决离异夫妇抚养孩子的一个协调过程。
3
If disputes over a contract develop, the parties shall, as far as possible, settle them through consultation, or through mediation by a thirdparty.