Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
danh hai » dang hai, lanh hai, manh hai
xach tay » canh tay
dan danh » van danh, han danh, ban danh
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
hai su » hai vu, lai su, hai so

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) or (xach tay)) ((nang ma) or (sang ma)) hoi. hieu van nam thuc dan danh hai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach y) OR (xach tay)) ((nang ma) OR (sang ma)) hoi. hieu van nam thuc dan danh hai su triet.
• Adding a wildcard symbol may retrieve word variants: su ((sach y) or (xach tay)) ((nang ma) or (sang ma)) hoi. hieu van nam thuc dan danh hai su triet*.