Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, cuoc cach, cuon sach
toc sach » doc sach, thuoc sach, toc san
hieu van » hieu va, thien van, lieu va
tinh tai » trinh tai, tinh thai, tinh hai
lam thuc » lam thuoc, am thuc, nam thuc
cau tren » cu tren, dau tren, ca tren
hoc sach » hoc sinh, hoc cac, hoc anh
van lam » van nam
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
tai cau » tai cac, tai cao
x hoi » xa hoi, o hoi, x ho

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) OR (nuoc sach))) or (hoc sach)) ky nang x hoi. hieu van lam thuc va tinh tai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((toc sach) OR (nuoc sach))) OR (hoc sach)) ky nang x hoi. hieu van lam thuc va tinh tai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((toc sach) OR (nuoc sach))) or (hoc sach)) ky nang x hoi. hieu van lam thuc va tinh tai cau tren".
• Adding a wildcard symbol may retrieve word variants: ((((toc sach) OR (nuoc sach))) or (hoc sach)) ky nang x hoi. hieu van lam thuc va tinh tai cau tren*.