< ts name="the growing book on data structures and algorithms"> < ts1 name="chap1" keywords="b-tree" URL="xxx/c1" type="mixed"> < ts11 name="sec1" URL="xxx/c1/s1" > < /ts11> < ts12 name="sec2" URL="xxx/c1/s2" > < ts121 name="Knuth-notation" URL="xxx/c1/s1#Knuth" > < /ts121> < /ts12> < /ts1> < ts2 name="chap2" keywords="dynamic hashing" URL="xxx/c2" type="mixed"> < ts21 name="sec1" URL="xxx/c2/s1" > < /ts21> < /ts2> < /ts>