1. Urquhart J. “Controlled-Release Pharmaceuticals”. American Pharmaceutical Association, Washington 1981; 13
2. Nimmo W S. “Drug Absorption”, L. F. Prescott, W. S. Nimmo. MTP Press Limited, Lancaster 1981; 11
3. Wilson C G. “Physiological Limitations To Novel Drug Delivery”. 1984; 8, 1–9 Interphex 84, Brighton, England, 26–29 June
4. Hunt J. N., Knox M. T. “Handbook of Physiology”. Am. Physiol. Soc., Washington 1968; vol 4: 1917–35, code, ed.