Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
hieu van » hieu va, thien van, lieu va
hang vai » hang tai, hang hai, hang vi
thuc dan » thuc hanh, hoc dan, thuc vat
van pham » san pham, van phan, van phat
te sach » toc sach
cao hoi » cau hoi, co hoi, cao hoc
ly hang » ly quang
ly vang » ly van, ly quang
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: te sach ((ly vang) or (ly hang)) cao hoi. hieu van pham thuc dan ((hang vai) OR (hang va)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ly vang) OR (ly hang)) cao hoi. hieu van pham thuc dan ((hang vai) OR (hang va)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ly vang) or (ly hang)) cao hoi. hieu van pham thuc dan ((hang vai) OR (hang va)) cua te".
• Adding a wildcard symbol may retrieve word variants: te sach ((ly vang) or (ly hang)) cao hoi. hieu van pham thuc dan ((hang vai) OR (hang va)) cua te*.