Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
cac dai » cac dan, cac bai, can dai
va danh » va dinh, va dan, va hanh
me hoi » le hoi
dai va » mai va
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((me hoi) or (mai hoi)). lieu va cac dai va danh ((vi cua) or (di cua)) vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((me hoi) OR (mai hoi)). lieu va cac dai va danh ((vi cua) OR (di cua)) vat.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((me hoi) or (mai hoi)). lieu va cac dai va danh ((vi cua) or (di cua)) vat*.