1. G.F. Bin'ko, V.N. Grebenev, Yu.B. Gurovet al., Prib. & Tekh. Eksp. Nu.4 (1990) 58. (English translation: Instrum, & Exp. Tech.33 (1990)).
2. V.G. Varlamov, B.A. Dolgoshein, Yu.P. Dobretsovet al., Nuovo Cimento36B (1976) 131.
3. V.A. Bashkirov, V.V. Govorov, Yu.P. Dobretsovet al., Pis'ma ZhETF29 (1979) 303. (English translation: Sov. Physics JETP Lett.29 (1979) 271).
4. Yu.P. Dobretsov, B.A. Dolgoshein and V.G. Kirillov-Ugriumov. Hyp. Int.18 (1084) 845.
5. V.N. Gorelkin and V.P. Smilga, ZhETF66 (1974) 1201. (English translation: Sov. Physics JETP39 (1974) 1586).