BibTeX does not have the right entry for preprints. This is a hack for producing the correct reference:
@booklet{EasyChair:440,
author = {Alexander J. Benavides},
title = {A New Tiebreaker in the NEH heuristic for the Permutation Flow Shop Scheduling Problem},
doi = {10.29007/ch1l},
howpublished = {EasyChair Preprint 440},
year = {EasyChair, 2018}}