Perhaps you should try some spelling variations:
pham tai » pham thi, pham van
van pham » san pham, van phan, van phat
tu sach » thu sach, su sach, te sach
cau duc » cao duc, cau luc, chu duc
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu van
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
hieu va » lieu va, hieu qua
cuc tu » cuc du, luc tu, duc tu

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 ((nang xa) or (lang xa)) hoi. ((hieu ve) or (hieu va)) cau duc van pham tai cuc tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (lang xa)) hoi. ((hieu ve) OR (hieu va)) cau duc van pham tai cuc tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (lang xa)) hoi. ((hieu ve) or (hieu va)) cau duc van pham tai cuc tu*.