  The gravitational lensing effect at higher order under weak-field
approximation is believed to be important to distinguish black holes and other
compact objects such as wormholes. The deflection angle of a generic wormhole
is difficult to solve analytically; thus approximation methods are implemented.
In this paper, we investigate the weak-field deflection angle of a specific
wormhole, the Ellis-Bronnikov wormhole, up to the 1/b^4 order. We use different
approximation formalisms, study their precision at 1/b^4 order by a comparison
to a purely numerical result, and finally rank these formalisms by their
accuracy. Moreover, we find that certain formalisms are sensitive to the choice
of coordinate system; thus it is important to choose the coordinate system
appropriately for the evaluating of lensing physics.
