Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
thu sach » thuat sach, thuoc sach, thu hoach
dan dinh » dang dinh, doan dinh, van dinh
thuc dan » thuc hanh, hoc dan, thuc vat
tang mai » tang ma, tang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
dinh va » dinh van, dinh ve, tinh va
ve nham » ve nha, ve cham
hieu ve » hieu va, hieu van
tu sach » su sach, te sach, tu cach
y tang » ky tang, 6 tang, 7 tang
cua tu » cua tuc, cua su, cua cu

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 (tu sach)) y tang mai khoi. hieu ve nham thuc dan dinh va ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) y tang mai khoi. hieu ve nham thuc dan dinh va ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (tu sach)) y tang mai khoi. hieu ve nham thuc dan dinh va ((cua te) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (tu sach)) y tang mai khoi. hieu ve nham thuc dan dinh va ((cua te) or (cua tu))*.