BibTeX does not have the right entry for preprints. This is a hack for producing the correct reference:
@Booklet{EasyChair:9453,
author = {Van Duc Nguyen and Trung Thuc Ngo and Anh Tuan Le and Ich Long Ngo and Viet Dung Duong},
title = {Lattice Boltzmann Method for Simulating Flow Over Moving Bodies},
howpublished = {EasyChair Preprint no. 9453},
year = {EasyChair, 2023}}
