Perhaps you should try some spelling variations:
cac khanh » cac thanh, cach nhanh, khac khanh
khanh hoa » thanh hoa, hang hoa
thu sach » tu sach, thuat sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
cuu cong » cua cong, thu cong, cac cong
cong cac » cuong cac, cong tac, cong cau
nhan dan » phan dau, gian dan, nhan tai
hoi van » hoi va, hai van, hoi han
hoi dan » hoa dan, hoc dan, hoi dap
hoc xa » hoc ma

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach hoc tap, nghien cuu cong cac khanh hoa hoc xa ((hoi van) OR (hoi dan)) nhan dan~".
• Adding a wildcard symbol may retrieve word variants: thu sach hoc tap, nghien cuu cong cac khanh hoa hoc xa ((hoi van) OR (hoi dan)) nhan dan*.