Perhaps you should try some spelling variations:
lanh dai » lanh dao, lanh hai, lang dai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
tang ma » tang van
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va lanh » va lang, va danh, va hanh
so viet » hoc viet
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa

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 ky ((tang ma) or (mang may)) hoi. hieu va cam tuc va lanh dai so viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((tang ma) OR (mang may)) hoi. hieu va cam tuc va lanh dai so viet.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((tang ma) or (mang may)) hoi. hieu va cam tuc va lanh dai so viet*.