@misc{ref20,
author = "",
title = "{G}rissom {CA}. {T}he deterioration and treatment of volcanic stone: a review of the literature. {I}n: {C}harola {AE}, {K}oestler {RJ}, {L}ombardi {G}, editors. {P}roceedings of the international meeting ``{L}avas and {V}olcanic {T}uffs'', {E}aster {I}sland, {C}hile, 25--31 {O}ctober 1990. p",
}