Perhaps you should try some spelling variations:
han thai » han tai, ban thai, van thai
pham duy » pham duc
cham duc » pham duc, cham soc, phan duc
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
sang ma » tang ma, nang ma, sang tao
thai va » thai van
va han » va phan, van han, va hanh
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((lang xa) or (sang ma)) hoi. hieu ve ((cham duc) or (pham duy)) va han thai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((lang xa) OR (sang ma)) hoi. hieu ve ((cham duc) OR (pham duy)) va han thai va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((lang xa) or (sang ma)) hoi. hieu ve ((cham duc) or (pham duy)) va han thai va thiet*.