The UMD Libraries have multiple print copies of Shakespeare's plays and poetry. The following search string in Worldcat will retrieve many of the Cambridge editions of his works along with their call numbers in McKeldin Library:
se: new cambridge shakespeare
You can also locate Arden editions of specific plays by searching in Worldcat. For example, the search terns : richard III arden will retrieve the Arden edition of Richard III. You can also search for all individual editions by using the following search terms: se:arden shakespeare
Bedford and Norton editions of specific plays are also excellent and contain a lot of historical and contextual information. They can be found in Worldcat. For example, the search terns : romeo and juliet bedford will retrieve editions of the play, Romeo and Juliet, published by Bedford. You can also search for all individual editions by using the following search terms: se: bedford shakespeare series. Norton editions can be found by searching the title of the play and the phrase norton critical edition: richard iii norton critical edition.
There are many adaptations of William Shakespeare's works which can be found by searching in Worldcat. For example, the following search will yield both print and film adaptations of the play Romeo and Juliet: ti:romeo juliet AND su:adaptations. Use this same convention for adaptations of other plays ti: title of play AND su:adaptations.