Sentence:  This viewpoint is <WSD>further</WSD> supported by Verloop 's ( ' 48 ) demonstration of thickened bronchial artery and arteriolar muscular coats which are capable of acting as valves . 
Meaning of the word marked with <WSD> tags:  to or at a greater extent or degree or a more advanced stage (`further' is used more often than `farther' in this abstract sense)