Perhaps you should try some spelling variations:
khang thuoc » khong thuoc, dang thuoc, hanh thuoc
van khang » van khanh, van thanh, van quang
thuoc ma » hoc ma, duoc ma
cua khau » cua khu, xuat khau, cua khach
khau tai » pham tai, nhan tai
su sach » vu sach
so sach » so sanh, bo sach, co sach
hoc van » hoc dan, hoc va, hoc vat
hoi cua » hoi chuc
mo hoc » mon hoc, co hoc
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (so sach)) hoc tap, nghien cuu mo hoc van khang thuoc ma hoi cua khau tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) hoc tap, nghien cuu mo hoc van khang thuoc ma hoi cua khau tai".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) hoc tap, nghien cuu mo hoc van khang thuoc ma hoi cua khau tai*.