Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hang doi » hang di, hang loi, huong doi
nam thuc » nam thuoc, am thuc, nam thu
trang xa » trang va, trang ha, trong xa
va hang » van hang, va nang, va lang
nam luc » nang luc, nhan luc, nam duoc
sach ky » sac ky, sach y, sach ty
tang xa » tang ma, lang xa, tang ha
cu tren » tu tren, dua tren
doi cu » doi cua, doi co, doi ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((tang xa) or (trang xa)) hoi. hieu van ((nam luc) or (nam thuc)) va hang doi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((tang xa) OR (trang xa)) hoi. hieu van ((nam luc) OR (nam thuc)) va hang doi cu tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((tang xa) or (trang xa)) hoi. hieu van ((nam luc) or (nam thuc)) va hang doi cu tren*.