Perhaps you should try some spelling variations:
hien manh » hien hanh, tien manh, hieu manh
trinh vat » trinh luat, sinh vat, trinh han
trinh van » trinh han, trinh quan, trinh toan
lang nong » hang nong, lang dong, lang song
nong dan » cong dan, nong san, nguong dan
dan chan » dan gian, dan ca, van chat
chan tu » phan tu, han tu, chon tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien manh - canh ((trinh vat) OR (trinh van)) lang nong dan chan tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien manh - canh ((trinh vat) OR (trinh van)) lang nong dan chan tu*".