Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va viet » hoa viet, san viet, mai viet
dan dan » dang dan, ban dan, dao dan
hieu va » lieu va, hieu qua
hieu ve » hieu van
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
co viet » so viet, o viet, hoc viet
ma hoi » mai hoi, xa hoi, ma hoa
dan vi » doan vi, don vi, dan va

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 ky sang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan dan vi ((va viet) or (co viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan dan vi ((va viet) OR (co viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky sang ma hoi. ((hieu ve) OR (hieu va)) nam thuc dan dan vi ((va viet) or (co viet))*".