Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
kham tuc » nham thuc, pham thuc, kham cuoc
hieu vu » hieu va, hieu ve, hieu su
vu kham » vu khanh
dan dat » dung dat, dong dat, dinh dat
dat cuu » dat cau, dat cua
cuu tre » cua tre, cau tren, cau treo
ma hoi » mai hoi, me hoi, va hoi
y nang » ky nang, ly nang, v nang
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau

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 y nang ((((ma hoi) OR (ma hoa))) or (xa hoi)). hieu vu kham tuc va dan dat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((((ma hoi) OR (ma hoa))) OR (xa hoi)). hieu vu kham tuc va dan dat cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((((ma hoi) OR (ma hoa))) or (xa hoi)). hieu vu kham tuc va dan dat cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((((ma hoi) OR (ma hoa))) or (xa hoi)). hieu vu kham tuc va dan dat cuu tre*.