Alex B. Wenzel, "A Review of Explosive Accelerators for Hypervelocity Impact," International Journal of Impact Engineering, Vol. 5, 1987, pp. 681-692.
A high explosive accelerates a small projectile up to 5.5 km/s.
E. N. Clark, A. Mackenzie, F. H. Schmitt and I. L. Kintish, "Studies of hypervelocity impact on lead," Proceedings of Fourth Hypervelocity Impact Symposium, Eglin AFB, Florida, 1960.
J. H. Kineke, "An experimental study of crater formation in metallic targets," Proceedings of Fourth Hypervelocity Impact Symposium, Eglin AFB, Florida, 1960.
A high explosive implodes a conical metal liner. The explosion fuses the liner into a thin liquid jet and accelerates it up to 16.5 km/s.
Alex B. Wenzel and J. W. Gehring, "Techniques for Launching 0.01 to 25 gm Discrete Projectiles at Velocities Up to 54,100 ft/sec," Proceedings of the Fourth Hypervelocity Techniques Symposium, Arnold Air Force Station, 1965.
A. E. Voitenko, "Generation of High-Speed Jets," Doklady Akademii Nauk SSSR, Vol. 158, 1964, pp. 1278-1280.
D. R. Sawle, "Characteristics of the Voitenko High-Explosive-Driven Gas Compressor," Acta Astronautica, Vol. 14, 1969, pp. 393-397.