Perhaps you should try some spelling variations:
su sach » so sach, vu sach
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
sach ty » sach y, sach tu, sach thu
lam va » nam va, lam ha, am va
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
ma hoi » mai hoi, xa hoi, ma hoa
dam va » dam van, nam va, dam ha
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 nang ma hoi. hieu ve chat ((xuc va) OR (tuc va)) hanh ((lam va) or (dam va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ma hoi. hieu ve chat ((xuc va) OR (tuc va)) hanh ((lam va) OR (dam va)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ma hoi. hieu ve chat ((xuc va) OR (tuc va)) hanh ((lam va) or (dam va)) thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ma hoi. hieu ve chat ((xuc va) OR (tuc va)) hanh ((lam va) or (dam va)) thiet*.