Incorporation of tramadol drug into Li-fluorohectorite clay: A preliminary study of a medical nanofluidL. Valdés, D. Hernández, L. Ch. de Ménorval, I. Pérez, E. Altshuler, J.O. Fossum and A. RiveraEur. Phys. J. Special Topics, 225 4 (2016) 767-771DOI: https://doi.org/10.1140/epjst/e2015-50323-x