1. Clinical evaluation of the Oculab Tono-Pen;Minckler, D.S.; Baerveldt, G.; Heuer, D.K.; Quillen-Thomas, B.; Walonker, A.F.; Weiner, J.;AmJ Ophthalmol,1987
2. Boothe WA, Lee DA, Panek WC, Pettit TH. The Tono-Pen. Arch Ophthalmol 1988; 106: 1214-7.
3. Tonometry in the general practice setting;Christoffersen, T.; Fors, T.; Ringberg, U.; Holtedahl, K.;Acta Ophthalmol; Goldmann applanation tonometry,1993
4. Evaluation of the Tono-Pen 2 and the X-Pert noncontact tonometers in cataract surgery;Denis, P.; Nordmann, J.-P.; Bertin, V.; Gayraud, J.-M.; Laroche, L.; Saraux, H.;Ophthalmologica,1993
5. Clinical comparison of the Oculab Tono-Pen to the Goldmann applanation tonometer;Kao, S.F.; Lichter, P.R.; Bergstrom, T.J.; Rowe, S.; Musch, D.C.;Ophthalmology,1987