Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
quan nam » quang nam, xuan nam, quan am
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
qua nam » cua nam, quang nam, qua nhat
vat dan » va dan, van dan, vat ran
vai cuu » vai cua

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 hoi. hieu ((qua nam) OR (quan nam)) thuc vat dan ((vai cuu) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu ((qua nam) OR (quan nam)) thuc vat dan ((vai cuu) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu ((qua nam) OR (quan nam)) thuc vat dan ((vai cuu) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu ((qua nam) OR (quan nam)) thuc vat dan ((vai cuu) or (dai cua)) tre*.