The New York Times API with R - r

Question

I'm trying to get articles' information using The New York Times API. The csv file I get doesn't reflect my filter query. For example, I restricted the source to 'The New York Times', but the file I got contains other sources also.
I would like to ask you why the filter query doesn't work.
Here's the code.
if (!require("jsonlite")) install.packages("jsonlite")
library(jsonlite)
api = "apikey"
nytime = function () {
url = paste('http://api.nytimes.com/svc/search/v2/articlesearch.json?',
'&fq=source:',("The New York Times"),'AND type_of_material:',("News"),
'AND persons:',("Trump, Donald J"),
'&begin_date=','20160522&end_date=','20161107&api-key=',api,sep="")
#get the total number of search results
initialsearch = fromJSON(url,flatten = T)
maxPages = round((initialsearch$response$meta$hits / 10)-1)
#try with the max page limit at 10
maxPages = ifelse(maxPages >= 10, 10, maxPages)
#creat a empty data frame
df = data.frame(id=as.numeric(),source=character(),type_of_material=character(),
web_url=character())
#save search results into data frame
for(i in 0:maxPages){
#get the search results of each page
nytSearch = fromJSON(paste0(url, "&page=", i), flatten = T)
temp = data.frame(id=1:nrow(nytSearch$response$docs),
source = nytSearch$response$docs$source,
type_of_material = nytSearch$response$docs$type_of_material,
web_url=nytSearch$response$docs$web_url)
df=rbind(df,temp)
Sys.sleep(5) #sleep for 5 second
}
return(df)
}
dt = nytime()
write.csv(dt, "trump.csv")
Here's the csv file I got.

Answer 1

It seems you need to put the () inside the quotes, not outside. Like this:
url = paste('http://api.nytimes.com/svc/search/v2/articlesearch.json?',
'&fq=source:',"(The New York Times)",'AND type_of_material:',"(News)",
'AND persons:',"(Trump, Donald J)",
'&begin_date=','20160522&end_date=','20161107&api-key=',api,sep="")
https://developer.nytimes.com/docs/articlesearch-product/1/overview