my wife and i are inviting my brother to travel to china from cameroon.i am a cameroonian living in china since the past seven years.and my wife is a chinese as well as our son.we are bother legally married according to the chinese law. i wish to know if inviting my brother in china will need any special invitation letter.i sent my brother an invitation letter with my compny stamp and also a letter of employment showing that i am a full time worker in china. is there any thing else to do for his visa issuance?