Xi'an-Shiyou-Daxue-xuebao 自然科学版. Ziran kexue ban. Volume 25 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1 Volume 24 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1 Volume 23 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1 Volume 22 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1 Volume 21 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1 Volume 20 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1