VAT (value added tax ) gaps and VAT evasion impact to the revenue . requirements : ? 

VAT gaps, tax revenue losses due to VAT avoidance and VAT evasion, in developing emerging countries.. ? 

What causes the VAT Gap? ?

 The role of vat legal system​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​?

 The impact in the GDP and the economic growth . 

The sources : LAW /legislation and Academic articles ,The OECD Revenue Statistics, 

World Development indicators Database, and The United Nations . Referencing : Please follow the OSCEOLA style requirement​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​s