William Shakespeare (2013). “Making Sense of Hamlet! a Students Guide to Shakespeare's Play (Includes Study Guide, Biography, and Modern Retelling)”, p.201, BookCaps Study Guides
Robert Burns, Robert Chambers (1838). “The Poetical Works of Robert Burns. To which are Now Added, Notes Illustrating Historical, Personal, and Local Allusions. [The Editor's Preface Signed: R. C., I.e. Robert Chambers.]”, p.85