Source:http://linkedlifedata.com/resource/umls/id/C1159693
GO: The directed movement of ammonium into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. Ammonium is the cation NH4+ which is formed from N2 by root-nodule bacteria in leguminous plants and is an excretory product in ammonotelic animals. [ISBN:0198506732]