The problem was solved simply by using an already standard character that had a similar sound to what the Viet called themselves.
( ( The problem ) ( ( was ( ( solved simply ) ( by ( using ( ( an ( already ( standard character ) ) ) ( that ( had ( ( a ( similar sound ) ) ( ( to what ) ( ( the Viet ) ( called themselves ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN problem)) (VP (VBD was) (VP (VBN solved) (ADVP (RB simply)) (PP (IN by) (S (VP (VBG using) (NP (NP (DT an) (RB already) (JJ standard) (NN character)) (SBAR (WHNP (WDT that)) (S (VP (VBD had) (NP (NP (DT a) (JJ similar) (NN sound)) (SBAR (WHPP (TO to) (WHNP (WP what))) (S (NP (DT the) (NNP Viet)) (VP (VBD called) (NP (PRP themselves))))))))))))))) (. .)))
The issue was worked around by substituting a character with a similar sound.
( ( The issue ) ( ( was ( ( worked around ) ( by ( ( substituting ( a character ) ) ( with ( a ( similar sound ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN issue)) (VP (VBD was) (VP (VBN worked) (PRT (RP around)) (PP (IN by) (S (VP (VBG substituting) (NP (DT a) (NN character)) (PP (IN with) (NP (DT a) (JJ similar) (NN sound)))))))) (. .)))