Using References (cont)
Examples of acceptable use of others' material:
and Smith  noted "M-trees do not assist Z queries".
and (Smith, 1998) noted "M-trees do not assist Z queries".
... and as was pointed out by Smith :
M-trees do not assist Z queries. Even if the Z queries
conform to the normal pattern of querying expected in
this context, the algorithmic complexity is still too high.