import re
from sys import stdin

text = stdin.read()

author = r"(?:[A-Z][A-Za-z'`-]+)"
etal = r"(?:et al\.?)"
additional = f"(?:,? (?:(?:and |& )?{author}|{etal}))"
year_num = "(?:19|20)[0-9][0-9]"
page_num = "(?:, p\.? [0-9]+)?"  # Always optional
year = fr"(?:, *{year_num}{page_num}| *\({year_num}{page_num}\))"
regex = fr'\b(?!(?:Although|Also)\b){author}{additional}*{year}'
matches = re.findall(regex, text)
matches = list( dict.fromkeys(matches) )
matches.sort()

#print(matches)
print ("\n".join(matches))