Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hanh hai » thanh hai, nhanh hai, hang hai
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cao hoi » cau hoi, co hoi, cao hoc
ly vang » ly hang, ly van, ly quang
va nam » van nam, ha nam, va nay
y nang » ky nang, ly nang, v nang

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 ((y nang) or (ly vang)) cao hoi. hieu va nam thuc dan hanh hai ((cau tao) or (cau thi))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ly vang)) cao hoi. hieu va nam thuc dan hanh hai ((cau tao) OR (cau thi)).
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (ly vang)) cao hoi. hieu va nam thuc dan hanh hai ((cau tao) or (cau thi))*.