extitisti
Wordlist from Comphistsem Frankfurt, Jan. 2016:
sg 2 IND act PF exto
Helmut Schmid's TreeTagger with Latin data by Gabriele Brandolini: exto V:IND
Georges, Ausführliches lateinisch-deutsches Handwörterbuch, 8. Aufl. (1913)
exto, s. exsto.
Lewis & Short, A latin dictionary (1879)
exto, exto, are, v. exsto.
Gaffiot, Dictionnaire latin-français (2016, ex 1934), merci à G. Gréco, M. De Wilde, B. Maréchal, K. Ôkubo!
exto extō, v. exsto.
Дворецкий И.Х., Отличный латинско-русский словарь (1976)
exto exto v. l. = exsto.
DuCange, Glossarium mediae et infimae latinitatis (1883-7)
EXTO, pro Esto, in Stat. crimin. Saonae cap. 27. pag. 54: Statuerunt quod pueri,... si cum frondis vel lapidibus manu jactis inter se rixati fuerint, condemnentur,... Exto quod non fuerint, doli capaces, vel etiam fuerint minores aetatis annorum quatuordecim,... etiam si lapsi vel lapides jacti per eos nullum percusserint.
Latinitatis medii aevi lexicon Bohemorum (thanks to the Centre for Classical Studies at the Institute of Philosophy of the Czech Academy of Sciences (www.ics.cas.cz/en)) (2017)
exto exto v. exsto
Köbler, Gerhard, Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter (thanks to the author, http://www.koeblergerhard.de/Mittellatein-HP/VorwortMlat-HP.htm) (2010)
exto extāre, lat., V.: Vw.: s. exstāre