The website for chinese embassy isn't openning here. Please let me know for india what are the documents I need to present at the visa office for geting a multiple entry 6 months business visa to China. I have a consultancy and will be taking students there. I have the following with me:

1) Invitation letter from the institute
2) Contract and license stating I am a liason Agent for the institute
3) Passport valid till 2015

What other documents do I need?