@article{ITA_1990__24_6_521_0,
     author = {Blanchet-Sadri, F.},
     title = {On dot-depth two},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {521--529},
     publisher = {EDP-Sciences},
     volume = {24},
     number = {6},
     year = {1990},
     mrnumber = {1082913},
     zbl = {0718.68046},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1990__24_6_521_0/}
}