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
tuong hoc » truong hoc, tuong ho, duong hoc
sach hoc » cach hoc, sach hoi, mach hoc
tung hoc » trung hoc, dung hoc, tung ho
thuoc ma » hoc ma, duoc ma
phap vat » phap luat, phap phat, phap viet
tu sach » thu sach, su sach, te sach
va phap » va phat, ban phap
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 hoc) OR (tuong hoc)) nganh khong thuoc ma hoi va phap vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach hoc tap, nghien huu ((tung hoc) OR (tuong hoc)) nganh khong thuoc ma hoi va phap vat".
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien huu ((tung hoc) OR (tuong hoc)) nganh khong thuoc ma hoi va phap vat*.