a three link works just like a four link. nothing like a two link. the diff. between a 3 and a 4 is that the upperbar is a wishbone shape on a 3 link. functions like a 4 link but since the top bars are only 1 piece they are only counted as 1 link. on a 4 link the upper bars are seperate. hope this makes sense.....
a true 3 link has 3 parrallel link bars and a panhard bar. 2 lower, and 1 upper link bars. the panhard takes care of the side to side movement.
a true 4 link has 4 link bars, and no panhard bar. the upper 2 bars are angled to replace the panhard bar.
a wishbone 3 link is very similair to a 4 link, it doesnt need a panhard bar at all. The only difference between a normal 4 link and a wishbone 3 link is on the 3 link, the upper triangled bars meet together in the front and have only 1 mounting point instead of 2 seperate ones.