Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dinh chi » dinh thi, dinh tri, dinh moi
va cham » va chat, va tham
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
ma hoi » mai hoi, xa hoi, ma hoa

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 y nang ma hoi. hieu ((ve cam) or (va cham)) duc va hanh ((dinh cuu) OR (dinh chi)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ma hoi. hieu ((ve cam) OR (va cham)) duc va hanh ((dinh cuu) OR (dinh chi)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ma hoi. hieu ((ve cam) or (va cham)) duc va hanh ((dinh cuu) OR (dinh chi)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ma hoi. hieu ((ve cam) or (va cham)) duc va hanh ((dinh cuu) OR (dinh chi)) tre*.