Perhaps you should try some spelling variations:
lang dai » lang hai, lang mai, lang chai
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
hai cua » thai cua, hoi cua, lai cua
luc van » luoc van, luu van, duc van
cam luc » cam xuc, cau luc
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
nang du » nang tu, nang luc, nang doc
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((lang dai) or (nang du)) hoi. hieu ve cam luc van hanh ((hai cua) OR (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((lang dai) OR (nang du)) hoi. hieu ve cam luc van hanh ((hai cua) OR (dai cua)) te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((lang dai) or (nang du)) hoi. hieu ve cam luc van hanh ((hai cua) OR (dai cua)) te*".