Perhaps you should try some spelling variations:
nang doc » nang luc
tan hanh » tan thanh, tang hanh, toan hanh
sach ky » sac ky, sach ty, sach kem
doc hoi » duoc hoi, hoc hoi, doc hai
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
tai cua » thai cua, tai cuc, dai cua
ve cam » ve cham, ve cac, va cam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sach y)) nang doc hoi. hieu ve cam duc tan hanh ((tai cua) or (tri cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang doc hoi. hieu ve cam duc tan hanh ((tai cua) OR (tri cua)) tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) nang doc hoi. hieu ve cam duc tan hanh ((tai cua) or (tri cua)) tre*.