Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
duc van » duc tan, duc manh, duc phan
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
vi cua » vai cua, di cua
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty nang ma hoi. hieu ve cac ((duc van) or (duc va)) hanh vi cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang ma hoi. hieu ve cac ((duc van) OR (duc va)) hanh vi cua cu.
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang ma hoi. hieu ve cac ((duc van) or (duc va)) hanh vi cua cu*.