Example snippet doesn't work for cited publication

[BetaUliansyah]

Hi, I tried to run scholarly example command in Google Colab but got this error:

MaxTriesExceededException

Code i run on Colab:
!pip install -U scholarly

!pip freeze | grep scholarly

scholarly==1.7.11

from scholarly import scholarly
# Retrieve the author's data, fill-in, and print
search_query = scholarly.search_author('Steven A Cholewiak')
author = scholarly.fill(next(search_query))
print(author)

# Print the titles of the author's publications
print([pub['bib']['title'] for pub in author['publications']])

# Take a closer look at the first publication
pub = scholarly.fill(author['publications'][0])
print(pub)

# Which papers cited that publication?
print([citation['bib']['title'] for citation in scholarly.citedby(pub)])

Three print results are fine. But last print result got MaxTriesExceededException

---

MaxTriesExceededException Traceback (most recent call last)
in
14
15 # Which papers cited that publication?
---> 16 print([citation['bib']['title'] for citation in scholarly.citedby(pub)])

5 frames
/usr/local/lib/python3.8/dist-packages/scholarly/_navigator.py in _get_page(self, pagerequest, premium)
188 return self._get_page(pagerequest, True)
189 else:
--> 190 raise MaxTriesExceededException("Cannot Fetch from Google Scholar.")
191
192

MaxTriesExceededException: Cannot Fetch from Google Scholar.

Same result also when I use ProxyGenerator.