How to remove citation parts that miss parentheses - r

Question

DATA
mystring1 <- "Other work has shown that, in addition to language-general features such as a decreased speaking rate and an expanded pitch range, clear speech production involves the enhancement of the acoustic-phonetic distance between phonologically contrastive categories 􏰃e.g., Ferguson and Kewley-Port, 2002; Krause and Braida, 2004, Picheny et al, 1986; Smiljanic and Bradlow, 2005, 2007􏰀."
mystring2 <- "Other work has shown that, in addition to language-general features such as a decreased speaking rate and an expanded pitch range, clear speech production involves the enhancement of the acoustic-phonetic distance between phonologically contrastive categories 􏰃e.g., Ferguson and Kewley-Port, 2002; Krause and Braida, 2004, Picheny et al, 1986; Smiljanic and Bradlow, 2005, 2007􏰀. Therefore, reduced sensitivity to any or all of the language-specific acoustic-phonetic dimensions of contrast and clear speech enhancement would yield a diminished clear speech benefit for non-native listeners. This may appear somewhat surprising given that clear speech production was elicited in our studies by instructing the talkers to speak clearly for the sake of listeners with either a hearing impairment or from a different native language background. However, as discussed further in Bradlow and Bent 􏰃2002􏰀, the limits of clear speech as a means of enhancing non-native speech perception likely reflect the “mistuning” that characterizes spoken language communication between native and non-native speakers."
I'd like to receive some help for regular expression. I got some text data. Basically I want to remove citation parts that appear between last word in a sentence and a period. However, parentheses are somehow missing. mystring1 is an example for that. In this example, I want to remove e.g., Ferguson and Kewley-Port, 2002; Krause and Braida, 2004, Picheny et al, 1986; Smiljanic and Bradlow, 2005, 2007􏰀. But this sentence is just one of the sentences in a paragraph. mystring2 contains three more sentences following mystring1. My goal is to remove the citation part from mystring2. But I have not been successful; the pattern is removing more texts than I want. How can I revise regex pattern? Thank you for your help in advance.
# This works for mystring1.
gsub(x = mystring1, pattern = "e\\.g\\.,.*[0-9]{4}(?=.)", replacement = "", perl = T)
[1] "Other work has shown that, in addition to language-general features such as a
decreased speaking rate and an expanded pitch range, clear speech production involves
the enhancement of the acoustic-phonetic distance between phonologically contrastive
categories 􏰃􏰀."
# But this pattern does not work for mystring2; gsub() removes texts more than I want.
gsub(x = mystring2, pattern = "e\\.g\\.,.*[0-9]{4}(?=.)", replacement = "", perl = T)
[1] "Other work has shown that, in addition to language-general features such as a decreased
speaking rate and an expanded pitch range, clear speech production involves the
enhancement of the acoustic-phonetic distance between phonologically contrastive
categories 􏰃􏰀, the limits of clear speech ... (I trimmed texts here) speakers."

Answer 1

I suggest using
\be\.g\.,.*?[0-9]{4}[^\w.]*(?=\.)
See the regex demo.
Details
\be\.g\. - a whole word e.g. (\b is a word boundary)
, - a comma
.*? - any 0+ chars other than line break chars (add (?s) at the pattern start to make it match line breaks, too)
[0-9]{4} - four digits
[^\w.]* - 0+ chars other than word chars and dot
(?=\.) - (a positive lookahead matching a location where) a . must be immediately to the right of the current location.
R demo:
rx <- "\\be\\.g\\.,.*?[0-9]{4}[^\\w.]*(?=\\.)"
gsub(x = mystring1, pattern = rx, replacement = "", perl = TRUE)
## => [1] "Other work has shown that, in addition to language-general features such as a decreased speaking rate and an expanded pitch range, clear speech production involves the enhancement of the acoustic-phonetic distance between phonologically contrastive categories 􏰃."
gsub(x = mystring2, pattern = rx, replacement = "", perl = TRUE)
## => [1] "Other work has shown that, in addition to language-general features such as a decreased speaking rate and an expanded pitch range, clear speech production involves the enhancement of the acoustic-phonetic distance between phonologically contrastive categories 􏰃. Therefore, reduced sensitivity to any or all of the language-specific acoustic-phonetic dimensions of contrast and clear speech enhancement would yield a diminished clear speech benefit for non-native listeners. This may appear somewhat surprising given that clear speech production was elicited in our studies by instructing the talkers to speak clearly for the sake of listeners with either a hearing impairment or from a different native language background. However, as discussed further in Bradlow and Bent 􏰃2002􏰀, the limits of clear speech as a means of enhancing non-native speech perception likely reflect the “mistuning” that characterizes spoken language communication between native and non-native speakers."