Perhaps you should try some spelling variations:
thien van » thi van
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
cong cu » chung cu
song xa » song cua
van cam » van nam, van lam, van cau

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 ky ((song xa) or (cong cu)) hoi. thien van cam thuc van ((hanh dai) or (lanh dao)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((song xa) OR (cong cu)) hoi. thien van cam thuc van ((hanh dai) OR (lanh dao)) va triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((song xa) or (cong cu)) hoi. thien van cam thuc van ((hanh dai) or (lanh dao)) va triet*.