Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
nganh khong » nganh cong, nhanh chong, nganh nong
nghien huu » nghien cuu, nguyen huu, nhiem huu
trung hoc » trung quoc
sach hoc » cach hoc, sach hoi, mach hoc
thuoc ma » hoc ma, duoc ma
tu sach » thu sach, su sach, te sach
tung ho » tuong ho, trung hoa, tong hop
va phap » va phat, ban phap
phap va » phap vat, pham va, pham van
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: tu sach hoc tap, nghien huu ((tung ho) or (trung hoc)) nganh khong thuoc ma hoi va phap va~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoc tap, nghien huu ((tung ho) OR (trung hoc)) nganh khong thuoc ma hoi va phap va.
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien huu ((tung ho) or (trung hoc)) nganh khong thuoc ma hoi va phap va*.