There are some name references from Shakespearean plays: Cassie Dorcas (Dorcas, a shepherdess in 'The Winter's Tale'), Jessica (Shylock's daughter in 'The Merchant of Venice'), Isabella Duke (Isabella in 'Measure for Measure')
The title, "Teach me, dear creature" comes from 'The Comedy of Errors': Act III Scene 2.
There are many quotations from 'Hamlet': 'Everlasting had not fixed. His canon 'gainst self-slaughter ..." from Act I Scene 2; 'O That this too solid flesh would melt' from Act I Scene 2; 'Though this be madness, yet there is method in 't.' from Act II Scene 2 ; 'To die, to sleep, to sleep, perchance to dream ..." from Act III Scene 1 ; 'Good night, sweet prince,. And flights of angels sing thee to thy rest!' from Act V Scene 2 ; 'something is rotten in the state of Denmark.' From Act I Scene 4.
"Parting is such sweet sorrow ... " comes from 'Romeo and Juliet':Act II Scene 2.
"Sound trumpets! - let our bloody colours wave; / And either victory or else a grave ..." comes from 'Henry VI, Part 3: Act II Scene 2.