ขั้นตอนวีซ่าถาวร
Immigrant Visa step
Submit a Petition (I-130)
Your Petition is Approved (NOA2)
Begin National Visa Center Processing
Pay Processing Fees
Establish Financial Support
Submit Documents to NVC
Submit Visa Application and Supporting Documents
Prepare for the Interview
Interview
http://travel.state.gov/content/visas/english/immigrate/immigrant-process/documents/fees.html/