Perhaps you should try some spelling variations:
va thuat » ky thuat, ki thuat, va thuc
thuat do » thuat o
cach tam » cach lam, cach ta, sach tham
tam than » ban than
canh tam » canh tac, canh tay, hanh tam
sanh va » hanh va, anh va, sinh va
tu cach » tu cac
than vo » than va, than doc, than hoc
tu canh » thu canh, tu chanh, tu can
do khi » doi khi, do thi, co khi
vo thi » do thi, vu thi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( do sanh va thuat do khi ) or ((( tu cach tam than vo thi ) OR ( tu canh tam than vo thi ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( do sanh va thuat do khi ) OR ((( tu cach tam than vo thi ) OR ( tu canh tam than vo thi )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( do sanh va thuat do khi ) or ((( tu cach tam than vo thi ) OR ( tu canh tam than vo thi ))))".
• Adding a wildcard symbol may retrieve word variants: (( do sanh va thuat do khi ) or ((( tu cach tam than vo thi ) OR ( tu canh tam than vo thi ))))*.