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
thuc va » thuc dan, thuc day
ma hoi » mai hoi, xa hoi, ma hoa
va nha » va nho, ve nha
de cua » le cua, te cua, dieu cua

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. lieu va nha ((thuc va) OR (thuc vat)) dinh ((de cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang ma hoi. lieu va nha ((thuc va) OR (thuc vat)) dinh ((de cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang ma hoi. lieu va nha ((thuc va) OR (thuc vat)) dinh ((de cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang ma hoi. lieu va nha ((thuc va) OR (thuc vat)) dinh ((de cua) or (dai cua)) tre*.