###Load libraries 

library(RCurl)
## Warning: package 'RCurl' was built under R version 3.2.3
## Loading required package: bitops
library(XML)
## Warning: package 'XML' was built under R version 3.2.3
library(plyr)
setwd("~/")

###Load HTML table for online Github repository 

book_html = readHTMLTable("book_data.html")
book_html.df = as.data.frame(book_html)
book_html.df
## data frame with 0 columns and 0 rows

###Load XML table for online Github repository 

book_xml = "book_data.xml"
book_xml.df = ldply(xmlToList("book_data.xml"), data.frame)
book_xml.df

###Load JSON table for online Github repository 

require(RJSONIO)
booksj = fromJSON("book_data.json", nullValue = NA, simplify = FALSE)
booksj
booksj.df = do.call("rbind", lapply(booksj, data.frame, stringAsFactors = FALSE))
booksj.df