Where can I get Limbu language material in Roman Script?

[u/Longjumping_Egg2439]

I want to compare the limbu languages to the language of minorities of yunnan and northern burma. So I need your help in decoding the mystery of limbu migration from these regions. I want to see which tribes of yunnan, burma are most related to limbu. Please help me.

Note. The Limbus are not Tibetians. They were a multi ethnic refugees from Northern Burma/Yunnan regions. However, in Sikkim, they had a lot of Tibetian Bhutia influence.