Where can you a white foam board that is big or huge in ho chi minh???

i had been in vietnam for almost 2 years but the first was kinda rough because i didnt know my native language so spend those studying so i have no idea where i can buy it. plz help!!!!

Was going to be silly and upload a picture i took last week of a motorbike with the passenger hold a big piece of styrofoam that you want but I cannot load it easliy.

So I saw a more productive idea today.
There are shops that sell tape wrapped foam boxes for food transport/storage. The Beige coloured ones
Maybe one of those can order/get/stock it.
At least they have a foam supplier.....

I am making an assumption that the foam you want is the same stuff.

you can go to those stationary shops opposite the architectural university in Dist 3. Corner of Nguyen Dinh Chieu and Pasteur St. They have many sizes.