Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
tru nang » tra nang, tri nang, truc nano
hanh dai » hanh tai, hanh dao, vanh dai
tu nang » tu nong, tu nano, tu lang
xa hanh » xa thanh, xa khanh, va hanh
co suc » cao suc, co su, cong suc
suc xa » tuc xa, buc xa, suc ma
dai va » mai va
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ((tu nang) or (tru nang)) xa hoi. lieu va co suc xa hanh dai va (thiet or thieu)~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((tu nang) OR (tru nang)) xa hoi. lieu va co suc xa hanh dai va (thiet OR thieu).
• Adding a wildcard symbol may retrieve word variants: doc sach ((tu nang) or (tru nang)) xa hoi. lieu va co suc xa hanh dai va (thiet or thieu)*.