https://www.literairnederland.nl/tag/de-madurese-vriend/
De Madurese vriend Archives - Literair Nederland
maduresevriendarchivesliterairnederland
https://www.languagecomparison.com/en/quechua-and-madurese-speaking-countries/comparison-78-94-3
Quechua and Madurese speaking Countries
Comparing Quechua vs Madurese countries gives you idea about number of countries.
quechuamaduresespeakingcountries
https://wals.info/valuesets/27A-mdr
WALS Online - Datapoint Madurese / Reduplication
wals onlinedatapointmaduresereduplication