Hagoromo chalk: Why the demise of a Japanese company is a blow to mathematics, The Independent

The Hagoromo Fulltouch Chalk was known as the
The Hagoromo Fulltouch Chalk was known as the 'Rolls Royce' of chalk

Hagoromo Bungu - Wikidata

How a brand of chalk achieved cult status among mathematicians

A Ride on the Assembly Line With the World's Most Famous Chalk - The New York Times

You have to fight the last anime character you saw. What will happen? - Quora

AN January/February 2023 by The Architect's Newspaper - Issuu

Hagoromo Bungu - Wikipedia

Did mathematicians really need to stockpile famed Japanese chalk?

What is the Japanese chalk that even told mathematicians that it is impossible to make a calculation error with this chalk? - GIGAZINE

Who is the best kicker (fighting) in anime? - Quora

How a brand of chalk achieved cult status among mathematicians

Volume 113 Issue 3 by The Stuyvesant Spectator - Issuu

Why Are Mathematicians Hoarding This Special Chalk?

Did mathematicians really need to stockpile famed Japanese chalk?