Found the following hamletworks.org entries referring to line 520

View Commentary Note for 520
520 Pol. Yet heere Laertes? a bord, a bord for shame,1.3.55

View Immaterial Textual Note for 520
520 Pol. Yet heere Laertes? a bord, a bord for shame,1.3.55

View Material Textual Note for 520
520 Pol. Yet heere Laertes? a bord, a bord for shame,1.3.55