Perhaps you should try some spelling variations:
thien van » thi van
sach thue » sach thu, sach thieu, sach tham
thue mang » thuat mang, thu hang, thu bang
thuc dan » thuc hanh, hoc dan, thuc vat
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
tu sach » thu sach, su sach, te sach
tay hoi » tay ho, tao hoi, tay thai
mai hoi » mai khoi, dai hoi, lai hoi
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua

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 thue mang ((mai hoi) or (tay hoi)). thien van cau ((truc va) or (thuc dan)) hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thue mang ((mai hoi) OR (tay hoi)). thien van cau ((truc va) OR (thuc dan)) hanh vi luu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thue mang ((mai hoi) or (tay hoi)). thien van cau ((truc va) or (thuc dan)) hanh vi luu tre*.