Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cam thuc » am thuc, nam thuc, cam thu
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
hieu va » lieu va, hieu qua
vu sach » vu bach, su sach, vu khach
ha hoi » hoa hoi, ha noi, xa hoi
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (vu sach)) ky lang ha hoi. hieu va cam thuc van hanh ((vi cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (vu sach)) ky lang ha hoi. hieu va cam thuc van hanh ((vi cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (vu sach)) ky lang ha hoi. hieu va cam thuc van hanh ((vi cua) or (dai cua)) tre*.