Another one Reference Guide from Aldec (NOT Evita!) with more detailed information about different constructions (I didn't find original link on Aldec site, so I've placed this one):
h**p://w+w.pldworld.com/_hdl/2/aldec/ref/Refguide/WHStart.htm
* -> t
+ -> w
Also, it's available in Active-HDL package as a single .chm file (refguide.chm).