▁B ▁K and el , ▁Richard ▁H ays ▁Williams : ▁Psych iat ric ▁re h abil itation : ▁some ▁problems ▁of ▁research . ▁New ▁York , ▁A ther ton ▁ 1 9 6 4 . ▁ ▁Den ise ▁By str yn ▁K and el , ▁Ger ald ▁S . ▁L esser : ▁Youth ▁in ▁two ▁world s . ▁San ▁Francisco , ▁Jos sey - B ass ▁ 1 9 7 2 , ▁. ▁ ▁Den ise ▁By str yn ▁K and el : ▁Long itud inal ▁Research ▁on ▁D rug ▁Use : ▁Emp ir ical ▁Find ings ▁and ▁Method ological ▁Iss ues . ▁Hal sted ▁Press ▁ 1 9 7 8 , ▁. ▁ ▁Den ise ▁B . ▁K and el : ▁Par ental ▁In flu ences ▁on ▁Ad oles cent ▁Mar iju ana ▁Use ▁And ▁The ▁Baby ▁Bo om ▁Generation : ▁Find ings ▁from ▁the ▁ 1 9 7 9 – 1 9 9 6 ▁National ▁House hold ▁Sur ve ys ▁on ▁D rug ▁Ab use . ▁U . S . ▁Government ▁Print ing ▁Office ▁ 2 0 0 1 , ▁. ▁ ▁Den ise ▁B . ▁K and el ▁( Ed .): ▁St ages ▁and ▁Path ways ▁of ▁D rug ▁In vol vement : ▁Ex am ining ▁the ▁Gate way ▁Hyp oth esis . ▁Cambridge ▁University ▁Press ▁ 2 0 0 2 , ▁. ▁ ▁References ▁ ▁External ▁links ▁▁ ▁Columbia ▁University ▁College ▁of ▁Phys icians ▁and ▁Sur ge ons : ▁Report ▁on ▁scientific ▁collaboration ▁of ▁Den ise ▁& ▁Eric ▁K