You do it through a written contract.

订立个书面合同.

And can do a written contract if required.

和可以做书面合同，如果需要的话。

He produced a written contract under seal.

他出示一张盖有印信的合约.

Do you execute a written contract, agreement or engagement letter for services with every client?

贵所是否与每位客户签订书面合同 、 协议或约定?

Is there a written contract with the transporter that moves containers from the factory to the port?

与将集装箱从工厂运至港口的运输商之间是否签订了书面合同？

AProfessional is a player who has a written contract with a club and is paidmore than the expenses he effectively incurs in return for his footballingactivity.

职业球员是指与俱乐部签订书面合同，且所得酬劳高于其足球活动花费的球员。