title: SUMIF with "ISNA" condition and for duplicate entries & for multiple criteria
body: <p>Solutions request for SUMIF for formula which is working for sumif for model qty sum with duplicate entries.</p>
  
  <p>Now, I'd like the formula to SUM the qty against each model (multiple entries) as above BUT with condition for each country.</p>
  
  <p>I am assuming that IF condition at the beginning would somehow give me solution but it returns error.</p>
  
  <p>Here's the link to the file
  <a href="https://drive.google.com/open?id=0B0aOVjxZjuyrOXkzN2RzbXlJTDg" rel="nofollow noreferrer">https://drive.google.com/open?id=0B0aOVjxZjuyrOXkzN2RzbXlJTDg</a></p>
  
  <p><a href="https://i.stack.imgur.com/sKyYH.png" rel="nofollow noreferrer">SUMIF formula example</a></p>
  
  <p>below is the formula I am currently using.</p>
  
  <pre><code>=IF(ISNA(VLOOKUP(A:A, Inventory!A:C, 4, 0)), "0", SUMIF(Inventory!A:A, Master!A3, Inventory!C:C))
  </code></pre>