Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
phan lap » phan dau
nang hoi » nang noi, nang hoc, nang ho
sach ty » sach tu, sach thu, xach tay
va phan » van phan, va phat, va phap
truc va » thuc va, thuc vat, trung va
hieu va » lieu va, hieu qua
hieu su » hieu sau, tieu su, hieu so
hoi hoi » hoi hoc, hoc hoi, hoi doi
lap su » lap du, lap tu, lai su

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 ty) OR (sach y)) nang hoi hoi. ((hieu su) or (hieu va)) cau truc va phan lap su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach y)) nang hoi hoi. ((hieu su) OR (hieu va)) cau truc va phan lap su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach y)) nang hoi hoi. ((hieu su) or (hieu va)) cau truc va phan lap su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach y)) nang hoi hoi. ((hieu su) or (hieu va)) cau truc va phan lap su triet*.