Charles Buck Theological Dictionary 
A religious order founded A. D. 1080, by one Brudo; so called from the desert Chartreux, the place of their institution. Their rule is extremely severe. They must not go out of their cells, except to church, without leave of their superior; nor speak to any person without leave. They must not keep any meat or drink till next day: their beds are of straw covered with a felt; their clothing, two hair cloths, two cowls, two pair of hose, and a cloak; all coarse. In the refectory they must keep their eyes on the dish, their hands on the table, their attention to the reader, and their hearts fixed on God. Women must not come into their churches.
The Nuttall Encyclopedia 
A monastic order of a very severe type, founded by St. Bruno in 1086, each member of which had originally a single cell, eventually one consisting of two or three rooms with a garden, all of them opening into one corridor; they amassed considerable wealth, but were given to deeds of benefaction, and spent their time in study and contemplation, in consequence of which they figure not so much in the outside world as many other orders do.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
Bibliography Information McClintock, John. Strong, James. Entry for 'Carthusians'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. https://www.studylight.org/encyclopedias/eng/tce/c/carthusians.html. Harper & Brothers. New York. 1870.