Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
cau treo » cau theo, cau tren, cau triet
sach ty » sach y, sach tu, sach thu
lang xa » dang xay, lang van
lang ha » long ha
dan dan » dang dan, ban dan, dao dan
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac

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 ((lang xa) or (lang ha)) hoi. hieu van nam thuc dan dan vai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((lang xa) OR (lang ha)) hoi. hieu van nam thuc dan dan vai cau treo.
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((lang xa) or (lang ha)) hoi. hieu van nam thuc dan dan vai cau treo*.