ROIC - which formula to use?

What ROIC formula is everybody using? There are at least 3 described in the book:

  • In Reading 29 says the denominator is calculated as operating assets less operating liabilities … “invested capital” means book values and exclude cash
  • In Reading 29 footnote says invested capital includes cash and cash equivalents … so include cash?
  • In Reading 32 says the denominator is total invested capital … since TIC=MVIC this would imply to use market values