Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
nang cho » nang chon, ngang cho, nang cao
cho hoc » co hoc, khoa hoc
hieu ve » hieu va, hieu van
duc van » duc va, duc manh, duc phan
cua cau » cua chu, cua cay, cua can
ve cac » va cac, vien 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 thi nang cho hoc. hieu ve cac ((duc van) or (duc tan)) hanh vi ((cua cau) OR (cua cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thi nang cho hoc. hieu ve cac ((duc van) OR (duc tan)) hanh vi ((cua cau) OR (cua cac))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thi nang cho hoc. hieu ve cac ((duc van) or (duc tan)) hanh vi ((cua cau) OR (cua cac))*".