what are the document needed to apply for business visa for Sri Lanka passport holder?

A valid passport, a completed Visa Application Form with a recently-taken passport photo, a Invitation Letter from you business partner and an official Invitation Letter obtained by your inviter, a supporting letter from the organization which you serve in, the latest 3 months original personal bank statement, photocopy of Certificate of Incorporation of applicant,photocopy of business license of the inviting entity,photocopy of ID of the one who signed the invitation letter.