Haspelmath, Martin. 1990. The grammaticalization of passive morphology. Studies in Language 14. 25-72.
@article{jacquesestimative-haspelmath90passive,
author = {Haspelmath, Martin},
journal = {Studies in Language},
number = {1},
pages = {25-72},
title = {The grammaticalization of passive morphology},
volume = {14},
year = {1990}
}