A análise de XML por R sempre retorna erro de declaração XML

Eu sou novo em XML. baixei um arquivo XML, chamado ipg140722, do google drive,http://www.google.com/googlebooks/uspto-patents-grants-text.html , Usei o Windows 8.1, R 3.1.1,

library(XML)
url<- "E:\\clouddownload\\R-download\\ipg140722.xml"
indata<- xmlTreeParse(url)

XML declaration allowed only at the start of the document
Extra content at the end of the document
error: 1: XML declaration allowed only at the start of the document
2: Extra content at the end of the document

  what is the problem

questionAnswers(1)

yourAnswerToTheQuestion