Hagen N. A., Fisher K. M., Lapointe B., Souich P. du, Chary S., Moulin D., Sellers E., Ngoc A. H.: An openlabel; multi-dose efficacy and safety study of intramuscular tetrodotoxin in patients with severe cancerrelated pain, J. Pain Symp. Manag., 34, 171-182(2007)