Perhaps you should try some spelling variations:
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
nhan tai » hang tai, van tai, toan tai
van nhan » van phan, van thanh, danh nhan
duc van » duc va, duc tan, duc manh
cau duc » cao duc, cau luc, chu duc
van cau » van dau, van hau, van chat
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tu » cua tuc, cua su, cua te
cua cu » cua chu, cua cau, cua su

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 ky ((nang xa) OR (nang ma)) hoi. thien van cau duc van nhan tai ((cua tu) or (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang xa) OR (nang ma)) hoi. thien van cau duc van nhan tai ((cua tu) OR (cua cu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((nang xa) OR (nang ma)) hoi. thien van cau duc van nhan tai ((cua tu) or (cua cu))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang xa) OR (nang ma)) hoi. thien van cau duc van nhan tai ((cua tu) or (cua cu))*.