Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
vat thanh » dat thanh, gat thanh, tat thanh
thanh dai » thanh hai, thanh tai, thanh dat
thu nang » thi nang, thu hang, thu bang
thi hang » thi hanh, thi nang, thi hong
so sach » so sanh, bo sach, co sach
quan am » quan nam, quan tam, quan ao
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((thu nang) or (thi hang)) ma hoi. hieu quan am thuc vat thanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((thu nang) OR (thi hang)) ma hoi. hieu quan am thuc vat thanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: so sach ((thu nang) or (thi hang)) ma hoi. hieu quan am thuc vat thanh dai cua te*.