Hello - My husband is a beginning student of the

Hello -

   My husband is a beginning student of the Italian language. I am trying to find a good workbook of beginner Italian language exercises for him. Does anyone have any recommendations of a workbook they have found useful? He is taking classes however they are ending for the summer. He would really like to continue with exercises over the summer so he does not lose the skills he has learned and also increase his vocabulary. 

Thank you!

Mary Jo