title: xlsxwriter refer to sheets inside worksheet.write_formula()
body: <p>I am trying to find a solution how to substitute the following:</p>
  
  <pre><code>worksheet = writer.sheets['Overview']
  worksheet.write_formula('C4', '=MIN('Sheet_147_mB'!C2:C325)')
  </code></pre>
  
  <p>with something like:</p>
  
  <pre><code>for s in sheet_names:
      worksheet.write_formula(row, col, '=MIN(s +'!C2:C325')')
      row+=1
  </code></pre>
  
  <p>to iterate through all the existing sheets in the current xlsx book and write the function to the current sheet having an overview.</p>
  
  <p>After spending some hours I was not able to find any solution therefore it would be hihgly appriciated if someone could point me to any direction. Thank you!</p>